Commit Graph

2698 Commits

Author SHA1 Message Date
Francesco Ruggeri c4dc304677 tty: Fix pty master poll() after slave closes v2
Commit f95499c303 ("n_tty: Don't wait for buffer work in read() loop")
introduces a race window where a pty master can be signalled that the pty
slave was closed before all the data that the slave wrote is delivered.
Commit f8747d4a46 ("tty: Fix pty master read() after slave closes") fixed the
problem in case of n_tty_read, but the problem still exists for n_tty_poll.
This can be seen by running 'for ((i=0; i<100;i++));do ./test.py ;done'
where test.py is:

import os, select, pty

(pid, pty_fd) = pty.fork()

if pid == 0:
   os.write(1, 'This string should be received by parent')
else:
   poller = select.epoll()
   poller.register( pty_fd, select.EPOLLIN )
   ready = poller.poll( 1 * 1000 )
   for fd, events in ready:
      if not events & select.EPOLLIN:
         print 'missed POLLIN event'
      else:
         print os.read(fd, 100)
   poller.close()

The string from the slave is missed several times.
This patch takes the same approach as the fix for read and special cases
this condition for poll.
Tested on 3.16.

Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06 12:23:36 -08:00
Jingchang Lu 7e12e675c1 serial: of-serial: fix uninitialized kmalloc variable
The info pointer points to an uninitialized kmalloced space.
If a device doesn't have clk property, then info->clk may
have unpredicated value and cause call trace. So use kzalloc
to make sure it is NULL initialized.

Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com>
Acked-by: Arnd Bergmann <arnd@arndb.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05 20:12:02 -08:00
Imre Deak 9e326f7871 tty/vt: don't set font mappings on vc not supporting this
We can call this function for a dummy console that doesn't support
setting the font mapping, which will result in a null ptr BUG. So check
for this case and return error for consoles w/o font mapping support.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=59321
Signed-off-by: Imre Deak <imre.deak@intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05 20:12:02 -08:00
Matthias Brugger cd92208f69 tty: serial: 8250_mtk: Fix quot calculation
The calculation of value quot for highspeed register set to three
was wrong. This patch fixes the calculation so that the serial port
for baudrates bigger then 576000 baud is working correctly.

Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05 20:12:02 -08:00
Peter Hurley 494c1eac7e tty: Prevent "read/write wait queue active!" log flooding
Only print one warning when a task is on the read_wait or write_wait
wait queue at final tty release.

Cc: <stable@vger.kernel.org> # 3.4.x+
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05 16:14:09 -08:00
Peter Hurley 37b1645788 tty: Fix high cpu load if tty is unreleaseable
Kernel oops can cause the tty to be unreleaseable (for example, if
n_tty_read() crashes while on the read_wait queue). This will cause
tty_release() to endlessly loop without sleeping.

Use a killable sleep timeout which grows by 2n+1 jiffies over the interval
[0, 120 secs.) and then jumps to forever (but still killable).

NB: killable just allows for the task to be rewoken manually, not
to be terminated.

Cc: <stable@vger.kernel.org> # since before 2.6.32
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05 16:14:09 -08:00
Peter Hurley 547039ec50 serial: Fix divide-by-zero fault in uart_get_divisor()
uart_get_baud_rate() will return baud == 0 if the max rate is set
to the "magic" 38400 rate and the SPD_* flags are also specified.
On the first iteration, if the current baud rate is higher than the
max, the baud rate is clamped at the max (which in the degenerate
case is 38400). On the second iteration, the now-"magic" 38400 baud
rate selects the possibly higher alternate baud rate indicated by
the SPD_* flag. Since only two loop iterations are performed, the
loop is exited, a kernel WARNING is generated and a baud rate of
0 is returned.

Reproducible with:
 setserial /dev/ttyS0 spd_hi base_baud 38400

Only perform the "magic" 38400 -> SPD_* baud transform on the first
loop iteration, which prevents the degenerate case from recognizing
the clamped baud rate as the "magic" 38400 value.

Reported-by: Robert Święcki <robert@swiecki.net>
Cc: <stable@vger.kernel.org> # all
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05 16:14:09 -08:00
Linus Torvalds 52d589a01d Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma
Pull slave-dmaengine updates from Vinod Koul:
 "For dmaengine contributions we have:
   - designware cleanup by Andy
   - my series moving device_control users to dmanegine_xxx APIs for
     later removal of device_control API
   - minor fixes spread over drivers mainly mv_xor, pl330, mmp, imx-sdma
     etc"

* 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma: (60 commits)
  serial: atmel: add missing dmaengine header
  dmaengine: remove FSLDMA_EXTERNAL_START
  dmaengine: freescale: remove FSLDMA_EXTERNAL_START control method
  carma-fpga: move to fsl_dma_external_start()
  carma-fpga: use dmaengine_xxx() API
  dmaengine: freescale: add and export fsl_dma_external_start()
  dmaengine: add dmaengine_prep_dma_sg() helper
  video: mx3fb: use dmaengine_terminate_all() API
  serial: sh-sci: use dmaengine_terminate_all() API
  net: ks8842: use dmaengine_terminate_all() API
  mtd: sh_flctl: use dmaengine_terminate_all() API
  mtd: fsmc_nand: use dmaengine_terminate_all() API
  V4L2: mx3_camer: use dmaengine_pause() API
  dmaengine: coh901318: use dmaengine_terminate_all() API
  pata_arasan_cf: use dmaengine_terminate_all() API
  dmaengine: edma: check for echan->edesc => NULL in edma_dma_pause()
  dmaengine: dw: export probe()/remove() and Co to users
  dmaengine: dw: enable and disable controller when needed
  dmaengine: dw: always export dw_dma_{en,dis}able
  dmaengine: dw: introduce dw_dma_on() helper
  ...
2014-10-18 18:11:04 -07:00
Vinod Koul 6b997bab20 serial: atmel: add missing dmaengine header
The atmel serial driver uses dmaengine APIs but never included the dmaengine
header as it was getting inculded thru one of driver headers.

commit 3d588f83e4 - "dmaengine: dw: split
dma-dw.h to platform and private parts" broke this as it moved headers
around.  Fix this by doing the right thing to include the dmaengine header

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Fixes: 08f738be88 (serial: at91: add tx dma support)
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-10-16 14:08:05 +05:30
Vinod Koul 2856fcdc1f Merge branch 'topic/dma_control_cleanup_acks' into for-linus 2014-10-15 21:38:49 +05:30
Vinod Koul 2bcd90d56c serial: sh-sci: use dmaengine_terminate_all() API
The drivers should use dmaengine_terminate_all() API instead of
accessing the device_control which will be deprecated soon

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-10-15 21:31:00 +05:30
Linus Torvalds faafcba3b5 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Optimized support for Intel "Cluster-on-Die" (CoD) topologies (Dave
     Hansen)

   - Various sched/idle refinements for better idle handling (Nicolas
     Pitre, Daniel Lezcano, Chuansheng Liu, Vincent Guittot)

   - sched/numa updates and optimizations (Rik van Riel)

   - sysbench speedup (Vincent Guittot)

   - capacity calculation cleanups/refactoring (Vincent Guittot)

   - Various cleanups to thread group iteration (Oleg Nesterov)

   - Double-rq-lock removal optimization and various refactorings
     (Kirill Tkhai)

   - various sched/deadline fixes

  ... and lots of other changes"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
  sched/dl: Use dl_bw_of() under rcu_read_lock_sched()
  sched/fair: Delete resched_cpu() from idle_balance()
  sched, time: Fix build error with 64 bit cputime_t on 32 bit systems
  sched: Improve sysbench performance by fixing spurious active migration
  sched/x86: Fix up typo in topology detection
  x86, sched: Add new topology for multi-NUMA-node CPUs
  sched/rt: Use resched_curr() in task_tick_rt()
  sched: Use rq->rd in sched_setaffinity() under RCU read lock
  sched: cleanup: Rename 'out_unlock' to 'out_free_new_mask'
  sched: Use dl_bw_of() under RCU read lock
  sched/fair: Remove duplicate code from can_migrate_task()
  sched, mips, ia64: Remove __ARCH_WANT_UNLOCKED_CTXSW
  sched: print_rq(): Don't use tasklist_lock
  sched: normalize_rt_tasks(): Don't use _irqsave for tasklist_lock, use task_rq_lock()
  sched: Fix the task-group check in tg_has_rt_tasks()
  sched/fair: Leverage the idle state info when choosing the "idlest" cpu
  sched: Let the scheduler see CPU idle states
  sched/deadline: Fix inter- exclusive cpusets migrations
  sched/deadline: Clear dl_entity params when setscheduling to different class
  sched/numa: Kill the wrong/dead TASK_DEAD check in task_numa_fault()
  ...
2014-10-13 16:23:15 +02:00
Linus Torvalds fd9879b9bb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux
Pull powerpc updates from Michael Ellerman:
 "Here's a first pull request for powerpc updates for 3.18.

  The bulk of the additions are for the "cxl" driver, for IBM's Coherent
  Accelerator Processor Interface (CAPI).  Most of it's in drivers/misc,
  which Greg & Arnd maintain, Greg said he was happy for us to take it
  through our tree.

  There's the usual minor cleanups and fixes, including a bit of noise
  in drivers from some of those.  A bunch of updates to our EEH code,
  which has been getting more testing.  Several nice speedups from
  Anton, including 20% in clear_page().

  And a bunch of updates for freescale from Scott"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (130 commits)
  cxl: Fix afu_read() not doing finish_wait() on signal or non-blocking
  cxl: Add documentation for userspace APIs
  cxl: Add driver to Kbuild and Makefiles
  cxl: Add userspace header file
  cxl: Driver code for powernv PCIe based cards for userspace access
  cxl: Add base builtin support
  powerpc/mm: Add hooks for cxl
  powerpc/opal: Add PHB to cxl mode call
  powerpc/mm: Add new hash_page_mm()
  powerpc/powerpc: Add new PCIe functions for allocating cxl interrupts
  cxl: Add new header for call backs and structs
  powerpc/powernv: Split out set MSI IRQ chip code
  powerpc/mm: Export mmu_kernel_ssize and mmu_linear_psize
  powerpc/msi: Improve IRQ bitmap allocator
  powerpc/cell: Make spu_flush_all_slbs() generic
  powerpc/cell: Move data segment faulting code out of cell platform
  powerpc/cell: Move spu_handle_mm_fault() out of cell platform
  powerpc/pseries: Use new defines when calling H_SET_MODE
  powerpc: Update contact info in Documentation files
  powerpc/perf/hv-24x7: Simplify catalog_read()
  ...
2014-10-11 20:34:00 -04:00
Linus Torvalds 81ae31d782 xen: features and fixes for 3.18-rc0
- Add pvscsi frontend and backend drivers.
 - Remove _PAGE_IOMAP PTE flag, freeing it for alternate uses.
 - Try and keep memory contiguous during PV memory setup (reduces
   SWIOTLB usage).
 - Allow front/back drivers to use threaded irqs.
 - Support large initrds in PV guests.
 - Fix PVH guests in preparation for Xen 4.5
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Merge tag 'stable/for-linus-3.18-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen updates from David Vrabel:
 "Features and fixes:

   - Add pvscsi frontend and backend drivers.
   - Remove _PAGE_IOMAP PTE flag, freeing it for alternate uses.
   - Try and keep memory contiguous during PV memory setup (reduces
     SWIOTLB usage).
   - Allow front/back drivers to use threaded irqs.
   - Support large initrds in PV guests.
   - Fix PVH guests in preparation for Xen 4.5"

* tag 'stable/for-linus-3.18-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (22 commits)
  xen: remove DEFINE_XENBUS_DRIVER() macro
  xen/xenbus: Remove BUG_ON() when error string trucated
  xen/xenbus: Correct the comments for xenbus_grant_ring()
  x86/xen: Set EFER.NX and EFER.SCE in PVH guests
  xen: eliminate scalability issues from initrd handling
  xen: sync some headers with xen tree
  xen: make pvscsi frontend dependant on xenbus frontend
  arm{,64}/xen: Remove "EXPERIMENTAL" in the description of the Xen options
  xen-scsifront: don't deadlock if the ring becomes full
  x86: remove the Xen-specific _PAGE_IOMAP PTE flag
  x86/xen: do not use _PAGE_IOMAP PTE flag for I/O mappings
  x86: skip check for spurious faults for non-present faults
  xen/efi: Directly include needed headers
  xen-scsiback: clean up a type issue in scsiback_make_tpg()
  xen-scsifront: use GFP_ATOMIC under spin_lock
  MAINTAINERS: Add xen pvscsi maintainer
  xen-scsiback: Add Xen PV SCSI backend driver
  xen-scsifront: Add Xen PV SCSI frontend driver
  xen: Add Xen pvSCSI protocol description
  xen/events: support threaded irqs for interdomain event channels
  ...
2014-10-11 20:29:01 -04:00
Linus Torvalds ef4a48c513 File locking related changes for v3.18 (pile #1)
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Merge tag 'locks-v3.18-1' of git://git.samba.org/jlayton/linux

Pull file locking related changes from Jeff Layton:
 "This release is a little more busy for file locking changes than the
  last:

   - a set of patches from Kinglong Mee to fix the lockowner handling in
     knfsd
   - a pile of cleanups to the internal file lease API.  This should get
     us a bit closer to allowing for setlease methods that can block.

  There are some dependencies between mine and Bruce's trees this cycle,
  and I based my tree on top of the requisite patches in Bruce's tree"

* tag 'locks-v3.18-1' of git://git.samba.org/jlayton/linux: (26 commits)
  locks: fix fcntl_setlease/getlease return when !CONFIG_FILE_LOCKING
  locks: flock_make_lock should return a struct file_lock (or PTR_ERR)
  locks: set fl_owner for leases to filp instead of current->files
  locks: give lm_break a return value
  locks: __break_lease cleanup in preparation of allowing direct removal of leases
  locks: remove i_have_this_lease check from __break_lease
  locks: move freeing of leases outside of i_lock
  locks: move i_lock acquisition into generic_*_lease handlers
  locks: define a lm_setup handler for leases
  locks: plumb a "priv" pointer into the setlease routines
  nfsd: don't keep a pointer to the lease in nfs4_file
  locks: clean up vfs_setlease kerneldoc comments
  locks: generic_delete_lease doesn't need a file_lock at all
  nfsd: fix potential lease memory leak in nfs4_setlease
  locks: close potential race in lease_get_mtime
  security: make security_file_set_fowner, f_setown and __f_setown void return
  locks: consolidate "nolease" routines
  locks: remove lock_may_read and lock_may_write
  lockd: rip out deferred lock handling from testlock codepath
  NFSD: Get reference of lockowner when coping file_lock
  ...
2014-10-11 13:21:34 -04:00
Linus Torvalds ea584595fc This is the bulk of GPIO changes for the v3.18 development
cycle:
 
 - Increase the default ARCH_NR_GPIO from 256 to 512. This
   was done to avoid having a custom <asm/gpio.h> header for
   the x86 architecture - GPIO is custom and complicated
   enough as it is already! We want to move to a radix to
   store the descriptors going forward, and finally get rid
   of this fixed array size altogether.
 
 - Endgame patching of the gpio_remove() semantics initiated
   by Abdoulaye Berthe. It is not accepted by the system that
   the removal of a GPIO chip fails during e.g. reboot or
   shutdown, and therefore the return value has now painfully
   been refactored away. For special cases like GPIO expanders
   on a hot-pluggable bus like USB, we may later add some
   gpiochip_try_remove() call, but for the cases we have now,
   return values are moot.
 
 - Some incremental refactoring of the gpiolib core and ACPI
   GPIO library for more descriptor usage.
 
 - Refactor the chained IRQ handler set-up method to handle
   also threaded, nested interrupts and set up the parent IRQ
   correctly. Switch STMPE and TC3589x drivers to use this
   registration method.
 
 - Add a .irq_not_threaded flag to the struct gpio_chip, so
   that also GPIO expanders that block but are still not
   using threaded IRQ handlers.
 
 - New drivers for the ARM64 X-Gene SoC GPIO controller.
 
 - The syscon GPIO driver has been improved to handle the
   "DSP GPIO" found on the TI Keystone 2 SoC:s.
 
 - ADNP driver switched to use gpiolib irqchip helpers.
 
 - Refactor the DWAPB driver to support being instantiated
   from and MFD cell (platform device).
 
 - Incremental feature improvement in the Zynq, MCP23S08,
   DWAPB, OMAP, Xilinx and Crystalcove drivers.
 
 - Various minor fixes.
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Merge tag 'gpio-v3.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO changes from Linus Walleij:
 "This is the bulk of GPIO changes for the v3.18 development cycle:

   - Increase the default ARCH_NR_GPIO from 256 to 512.  This was done
     to avoid having a custom <asm/gpio.h> header for the x86
     architecture - GPIO is custom and complicated enough as it is
     already! We want to move to a radix to store the descriptors going
     forward, and finally get rid of this fixed array size altogether.

   - Endgame patching of the gpio_remove() semantics initiated by
     Abdoulaye Berthe.  It is not accepted by the system that the
     removal of a GPIO chip fails during eg reboot or shutdown, and
     therefore the return value has now painfully been refactored away.
     For special cases like GPIO expanders on a hot-pluggable bus like
     USB, we may later add some gpiochip_try_remove() call, but for the
     cases we have now, return values are moot.

   - Some incremental refactoring of the gpiolib core and ACPI GPIO
     library for more descriptor usage.

   - Refactor the chained IRQ handler set-up method to handle also
     threaded, nested interrupts and set up the parent IRQ correctly.
     Switch STMPE and TC3589x drivers to use this registration method.

   - Add a .irq_not_threaded flag to the struct gpio_chip, so that also
     GPIO expanders that block but are still not using threaded IRQ
     handlers.

   - New drivers for the ARM64 X-Gene SoC GPIO controller.

   - The syscon GPIO driver has been improved to handle the "DSP GPIO"
     found on the TI Keystone 2 SoC:s.

   - ADNP driver switched to use gpiolib irqchip helpers.

   - Refactor the DWAPB driver to support being instantiated from and
     MFD cell (platform device).

   - Incremental feature improvement in the Zynq, MCP23S08, DWAPB, OMAP,
     Xilinx and Crystalcove drivers.

   - Various minor fixes"

* tag 'gpio-v3.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (52 commits)
  gpio: pch: Build context save/restore only for PM
  pinctrl: abx500: get rid of unused variable
  gpio: ks8695: fix 'else should follow close brace '}''
  gpio: stmpe: add verbose debug code
  gpio: stmpe: fix up interrupt enable logic
  gpio: staticize xway_stp_init()
  gpio: handle also nested irqchips in the chained handler set-up
  gpio: set parent irq on chained handlers
  gpiolib: irqchip: use irq_find_mapping while removing irqchip
  gpio: crystalcove: support virtual GPIO
  pinctrl: bcm281xx: make Kconfig dependency more strict
  gpio: kona: enable only on BCM_MOBILE or for compile testing
  gpio, bcm-kona, LLVMLinux: Remove use of __initconst
  gpio: Fix ngpio in gpio-xilinx driver
  gpio: dwapb: fix pointer to integer cast
  gpio: xgene: Remove unneeded #ifdef CONFIG_OF guard
  gpio: xgene: Remove unneeded forward declation for struct xgene_gpio
  gpio: xgene: Fix missing spin_lock_init()
  gpio: ks8695: fix switch case indentation
  gpiolib: add irq_not_threaded flag to gpio_chip
  ...
2014-10-09 14:58:15 -04:00
Linus Torvalds 683a52a101 TTY/Serial driver patches for 3.18-rc1
Here's the big tty/serial driver patchset for 3.18-rc1.
 
 Lots of little things in here, some good work from Peter Hurley on the
 tty core, and in lots of drivers.  There are also lots of other driver
 updates in here as well, full details in the changelog below.
 
 All have been in the linux-next tree for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here's the big tty/serial driver patchset for 3.18-rc1.

  Lots of little things in here, some good work from Peter Hurley on the
  tty core, and in lots of drivers.  There are also lots of other driver
  updates in here as well, full details in the changelogs.

  All have been in the linux-next tree for a while"

* tag 'tty-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (99 commits)
  Revert "serial/core: Initialize the console pm state"
  tty: serial: 8250: use 32bit variable for rpm_tx_active
  tty: serial: msm: Add earlycon support
  serial/core: Initialize the console pm state
  serial: asc: Conditionally use readl_relaxed (COMPILE_TEST)
  serial: of-serial: add PM suspend/resume support
  m68k: AMIGA_BUILTIN_SERIAL should depend on TTY
  asm/uapi: Add definition of TIOC[SG]RS485
  tty/metag_da: Add console_poll module parameter
  serial: 8250_pci: remove rts_n override from Baytrail quirk
  serial: cadence: Add generic earlycon support
  serial: imx: change the wait even to interruptiable
  serial: imx: terminate the RX DMA when the UART is suspending
  serial: imx: fix throttle/unthrottle callbacks for hardware assisted flow control
  serial: 8250: Add Quark X1000 to 8250_pci.c
  tty: omap-serial: pull out calculation from baud_is_mode16
  tty: omap-serial: fix division by zero
  xen_hvc: no reason to write the type key on xenstore
  tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx()
  tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused()
  ...
2014-10-08 06:52:11 -04:00
Linus Torvalds bdf428feb2 Nothing major: support for compressing modules, and auto-tainting params.
Cheers,
 Rusty.
 PS.  My virtio-next tree is empty: DaveM took the patches I had.  There might
      be a virtio-rng starvation fix, but so far it's a bit voodoo so I will
      get to that in the next two days or it will wait.
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Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module update from Rusty Russell:
 "Nothing major: support for compressing modules, and auto-tainting
  params.

  PS. My virtio-next tree is empty: DaveM took the patches I had.  There
      might be a virtio-rng starvation fix, but so far it's a bit voodoo
      so I will get to that in the next two days or it will wait"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  moduleparam: Resolve missing-field-initializer warning
  kbuild: handle module compression while running 'make modules_install'.
  modinst: wrap long lines in order to enhance cmd_modules_install
  modsign: lookup lines ending in .ko in .mod files
  modpost: simplify file name generation of *.mod.c files
  modpost: reduce visibility of symbols and constify r/o arrays
  param: check for tainting before calling set op.
  drm/i915: taint the kernel if unsafe module parameters are set
  module: add module_param_unsafe and module_param_named_unsafe
  module: make it possible to have unsafe, tainting module params
  module: rename KERNEL_PARAM_FL_NOARG to avoid confusion
2014-10-07 20:17:38 -04:00
David Vrabel 95afae4814 xen: remove DEFINE_XENBUS_DRIVER() macro
The DEFINE_XENBUS_DRIVER() macro looks a bit weird and causes sparse
errors.

Replace the uses with standard structure definitions instead.  This is
similar to pci and usb device registration.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-10-06 10:27:57 +01:00
Greg Kroah-Hartman 69784fa539 Revert "serial/core: Initialize the console pm state"
This reverts commit a86713b153.

Kevin Hilman writes:

	Multiple boot failures on ARM[1] were bisected down to this
	patch.

	How was this patch tested, and on which platforms?

	Also, the changelog states that this should be done only for
	UART_CAP_SLEEP, but the patch does it for every UART.

	Greg, I suggest this patch be dropped from tty-next until it has
	been better described and tested.

	[1] http://lists.linaro.org/pipermail/kernel-build-reports/2014-October/005550.html

Reported-by: Kevin Hilman <khilman@kernel.org>
Cc: Sudhir Sreedharan <ssreedharan@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-02 21:33:50 -07:00
Anton Blanchard 3e47d1474c powerpc: Remove powerpc specific cmd_line
There is no need for yet another copy of the command line, just
use boot_command_line like everyone else.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-02 17:33:55 +10:00
Stephen Boyd 0efe729634 tty: serial: msm: Add earlycon support
Add support for DT based and command line based early console on platforms
with the msm serial hardware.

Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:49:48 -04:00
Sudhir Sreedharan a86713b153 serial/core: Initialize the console pm state
For console devices having UART_CAP_SLEEP capability, the uart_pm_state has
to be initialized to UART_PM_STATE_ON. Otherwise the LCR regiser values
are reinitialized when uart_change_pm is called from uart_configure_port.

Signed-off-by: Sudhir Sreedharan <ssreedharan@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:49:48 -04:00
Daniel Thompson daea65a7be serial: asc: Conditionally use readl_relaxed (COMPILE_TEST)
Commit 08177ece59 ("serial: asc: Adopt readl_/writel_relaxed()) is
regressing the m68k allmodconfig build. This is due to the unconditional
use of readl_relaxed() which, although documented, does not currently
exist for m68k.

This is trivially fixable for st-asc because we can just update the
asc_in() accessor to make this conditional.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com>
Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:49:48 -04:00
Jingchang Lu 2dea53bf57 serial: of-serial: add PM suspend/resume support
This adds PM suspend/resume support for the of-serial driver
to provide power management support on devices attatched to it.

Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:49:13 -04:00
James Hogan c3f43eec80 tty/metag_da: Add console_poll module parameter
Currently the metag_da console channel is write only, it doesn't get
polled for incoming data. This is for performance & latency reasons as
polling blocks the processor for a significant amount of time waiting
for the JTAG probe to respond to the request and restart the thread.
This means that the console channel cannot be used for a login prompt,
so ttyDA2 is usually used instead.

In a virtual environment with a virtual DA such as QEMU however the
polling is much cheaper as the request can be handled immediately. It is
useful to be able to enable polling in such an environment in order to
get both the kernel log and a usable login prompt on the same DA
channel.

Add a console_poll module parameter which allows polling to be enabled
for the console channel. It defaults to off as that is the current
behaviour for good reason on real hardware.

It can be enabled by appending metag_da.console_poll to the kernel
command line.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:35:56 -04:00
Heikki Krogerus 716e115cd7 serial: 8250_pci: remove rts_n override from Baytrail quirk
It should not be used together with Auto Flow Control, and
Auto Flow Control is always enabled on Baytrail.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:35:56 -04:00
Michal Simek 6fa62fc46e serial: cadence: Add generic earlycon support
Add earlycon support for the cadence serial port.
This is based on recent patches:
"tty/serial: pl011: add generic earlycon support"
(sha1: 0d3c673e78)
"tty/serial: add arm/arm64 semihosting earlycon"
(sha1: d50d7269eb)

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:32:37 -04:00
Huang Shijie a4688bcd34 serial: imx: change the wait even to interruptiable
The wait_event() makes the application hang for ever in the following case:
 [1] the hardware flow control is enabled.
 [2] the other end (or the remote end) is terminated, and the TX is still
     waiting for the hardware flow control signal to become asserted.

This patch fixes it by changing the wait_event to wait_event_interruptible.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:26:38 -04:00
Huang Shijie 45564a6656 serial: imx: terminate the RX DMA when the UART is suspending
When the uart port is suspending, the RX data is useless.
So in this case, we can terminate the RX DMA right now.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:26:38 -04:00
Fugang Duan bb2f861ad0 serial: imx: fix throttle/unthrottle callbacks for hardware assisted flow control
when the 'CTSC' bit is negated. 'CTS' has no function when 'CTSC' is asserted.
0: The CTS pin is high (inactive)
1: The CTS pin is low (active)

For throttle, it needs to clear 'CTS' and 'CTSC' bits.
For unthrottle, it needs to enable 'CTS' and 'CTSC' bits.

The patch just fix the issue.

Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:26:38 -04:00
Bryan O'Donoghue 1ede7dcca3 serial: 8250: Add Quark X1000 to 8250_pci.c
Quark X1000 contains two designware derived 8250 serial ports.
Each port has a unique PCI configuration space consisting of
BAR0:UART BAR1:DMA respectively.

Unlike the standard 8250 the register width is 32 bits for RHR,IER etc
The Quark UART has a fundamental clock @ 44.2368 MHz allowing for a
bitrate of up to about 2.76 megabits per second.

This patch enables standard 8250 mode

Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:25:21 -04:00
Frans Klaver 13d6ceb4c4 tty: omap-serial: pull out calculation from baud_is_mode16
To determine the correct divisor, we need to know the difference between
the desired baud rate and the actual baud rate. The calculation for this
difference is implemented twice within omap_serial_baud_is_mode16().
Pull out the calculation for easier maintenance.

While at it, remove the CamelCasing from the variable names.

Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:24:06 -04:00
Frans Klaver dc3187564e tty: omap-serial: fix division by zero
If the chosen baud rate is large enough (e.g. 3.5 megabaud), the
calculated n values in serial_omap_is_baud_mode16() may become 0. This
causes a division by zero when calculating the difference between
calculated and desired baud rates. To prevent this, cap the n13 and n16
values on 1.

Division by zero in kernel.
[<c00132e0>] (unwind_backtrace) from [<c00112ec>] (show_stack+0x10/0x14)
[<c00112ec>] (show_stack) from [<c01ed7bc>] (Ldiv0+0x8/0x10)
[<c01ed7bc>] (Ldiv0) from [<c023805c>] (serial_omap_baud_is_mode16+0x4c/0x68)
[<c023805c>] (serial_omap_baud_is_mode16) from [<c02396b4>] (serial_omap_set_termios+0x90/0x8d8)
[<c02396b4>] (serial_omap_set_termios) from [<c0230a0c>] (uart_change_speed+0xa4/0xa8)
[<c0230a0c>] (uart_change_speed) from [<c0231798>] (uart_set_termios+0xa0/0x1fc)
[<c0231798>] (uart_set_termios) from [<c022bb44>] (tty_set_termios+0x248/0x2c0)
[<c022bb44>] (tty_set_termios) from [<c022c17c>] (set_termios+0x248/0x29c)
[<c022c17c>] (set_termios) from [<c022c3e4>] (tty_mode_ioctl+0x1c8/0x4e8)
[<c022c3e4>] (tty_mode_ioctl) from [<c0227e70>] (tty_ioctl+0xa94/0xb18)
[<c0227e70>] (tty_ioctl) from [<c00cf45c>] (do_vfs_ioctl+0x4a0/0x560)
[<c00cf45c>] (do_vfs_ioctl) from [<c00cf568>] (SyS_ioctl+0x4c/0x74)
[<c00cf568>] (SyS_ioctl) from [<c000e480>] (ret_fast_syscall+0x0/0x30)

Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:23:45 -04:00
Stefano Stabellini fb498df078 xen_hvc: no reason to write the type key on xenstore
The backend type is chosen by the toolstack. Regardless, the frontend
should not care, especially given that it cannot have an effect as the
backend is started before this code is run.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:23:45 -04:00
Sebastian Andrzej Siewior 9137568e73 tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx()
serial8250_do_startup() adds UART_IER_RDI and UART_IER_RLSI to ier.
serial8250_stop_rx() should remove both.
This is what the serial-omap driver has been doing and is now moved to
the 8250-core since it does no look to be *that* omap specific.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-26 18:01:56 +02:00
Sebastian Andrzej Siewior 59b3e898dd tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused()
Tony noticed that the old omap-serial driver picked the uart "number"
based on the hint given from device tree or platform device's id.
The 8250 based omap driver doesn't do this because the core code does
not honour the ->line argument which is passed by the driver.

This patch aims to keep the same behaviour as with omap-serial. The
function will first try to use the line suggested ->line argument and
then fallback to the old strategy in case the port is taken.

That means the the third uart will always be ttyS2 even if the previous
two have not been enabled in DT.

Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-26 18:01:56 +02:00
Sebastian Andrzej Siewior 0aa525d118 tty: serial: 8250_core: read only RX if there is something in the FIFO
The serial8250_do_startup() function unconditionally clears the
interrupts and for that it reads from the RX-FIFO without checking if
there is a byte in the FIFO or not. This works fine on OMAP4+ HW like
AM335x or DRA7.
OMAP3630 ES1.1 (which means probably all OMAP3 and earlier) does not like
this:

|Unhandled fault: external abort on non-linefetch (0x1028) at 0xfb020000
|Internal error: : 1028 [#1] ARM
|Modules linked in:
|CPU: 0 PID: 1 Comm: swapper Not tainted 3.16.0-00022-g7edcb57-dirty #1213
|task: de0572c0 ti: de058000 task.ti: de058000
|PC is at mem32_serial_in+0xc/0x1c
|LR is at serial8250_do_startup+0x220/0x85c
|Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
|Control: 10c5387d  Table: 80004019  DAC: 00000015
|[<c03051d4>] (mem32_serial_in) from [<c0307fe8>] (serial8250_do_startup+0x220/0x85c)
|[<c0307fe8>] (serial8250_do_startup) from [<c0309e00>] (omap_8250_startup+0x5c/0xe0)
|[<c0309e00>] (omap_8250_startup) from [<c030863c>] (serial8250_startup+0x18/0x2c)
|[<c030863c>] (serial8250_startup) from [<c030394c>] (uart_startup+0x78/0x1d8)
|[<c030394c>] (uart_startup) from [<c0304678>] (uart_open+0xe8/0x114)
|[<c0304678>] (uart_open) from [<c02e9e10>] (tty_open+0x1a8/0x5a4)

Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-26 18:01:56 +02:00
Sebastian Andrzej Siewior d74d5d1b72 tty: serial: 8250_core: add run time pm
While comparing the OMAP-serial and the 8250 part of this I noticed that
the latter does not use run time-pm. Here are the pieces. It is
basically a get before first register access and a last_busy + put after
last access. This has to be enabled from userland _and_ UART_CAP_RPM is
required for this.
The runtime PM can usually work transparently in the background however
there is one exception to this: After serial8250_tx_chars() completes
there still may be unsent bytes in the FIFO (depending on CPU speed vs
baud rate + flow control). Even if the TTY-buffer is empty we do not
want RPM to disable the device because it won't send the remaining
bytes. Instead we leave serial8250_tx_chars() with RPM enabled and wait
for the FIFO empty interrupt. Once we enter serial8250_tx_chars() with
an empty buffer we know that the FIFO is empty and since we are not going
to send anything, we can disable the device.
That xchg() is to ensure that serial8250_tx_chars() can be called
multiple times and only the first invocation will actually invoke the
runtime PM function. So that the last invocation of __stop_tx() will
disable runtime pm.

NOTE: do not enable RPM on the device unless you know what you do! If
the device goes idle, it won't be woken up by incomming RX data _unless_
there is a wakeup irq configured which is usually the RX pin configure
for wakeup via the reset module. The RX activity will then wake up the
device from idle. However the first character is garbage and lost. The
following bytes will be received once the device is up in time. On the
beagle board xm (omap3) it takes approx 13ms from the first wakeup byte
until the first byte that is received properly if the device was in
core-off.

v5…v8:
	- drop RPM from serial8250_set_mctrl() it will be used in
	  restore path which already has RPM active and holds
	  dev->power.lock
v4…v5:
	- add a wrapper around rpm function and introduce UART_CAP_RPM
	  to ensure RPM put is invoked after the TX FIFO is empty.
v3…v4:
	- added runtime to the console code
	- removed device_may_wakeup() from serial8250_set_sleep()

Cc: mika.westerberg@linux.intel.com
Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-26 18:01:56 +02:00
Sebastian Andrzej Siewior 234abab143 tty: serial: 8250_core: allow to set ->throttle / ->unthrottle callbacks
The OMAP UART provides support for HW assisted flow control. What is
missing is the support to throttle / unthrottle callbacks which are used
by the omap-serial driver at the moment.
This patch adds the callbacks. It should be safe to add them since they
are only invoked from the serial_core (uart_throttle()) if the feature
flags are set.

Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-26 18:01:56 +02:00
Peter Hurley c274f6ef1c tty: Hold termios_rwsem for tcflow(TCIxxx)
While transmitting a START/STOP char for tcflow(TCION/TCIOFF), prevent
a termios change. Otherwise, a garbage in-band flow control char
may be sent, if the termios change overlaps the transmission setup.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 21:19:36 -07:00
Peter Hurley 136d5258b2 tty: Move and rename send_prio_char() as tty_send_xchar()
Relocate the file-scope function, send_prio_char(), as a global
helper tty_send_xchar(). Remove the global declarations for
tty_write_lock()/tty_write_unlock(), as these are file-scope only now.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 21:19:35 -07:00
Peter Hurley c545b66c69 tty: Serialize tcflow() with other tty flow control changes
Use newly-introduced tty->flow_lock to serialize updates to
tty->flow_stopped (via tcflow()) and with concurrent tty flow
control changes from other sources.

Merge the storage for ->stopped and ->flow_stopped, now that both
flags are serialized by ->flow_lock.

The padding bits are necessary to force the compiler to allocate the
type specified; otherwise, gcc will ignore the type specifier and
allocate the minimum number of bytes necessary to store the bitfield.
In turn, this would allow Alpha EV4 and EV5 cpus to corrupt adjacent
byte storage because those cpus use RMW to store byte and short data.

gcc versions < 4.7.2 will also corrupt storage adjacent to bitfields
smaller than unsigned long on ia64, ppc64, hppa64 and sparc64, thus
requiring more than unsigned int storage (which would otherwise be
sufficient to workaround the Alpha non-atomic byte/short storage problem).

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 21:19:35 -07:00
Peter Hurley 01adc80706 tty: Move packet mode flow control notifications to pty driver
When a master pty is set to packet mode, flow control changes to
the slave pty cause notifications to the master pty via reads and
polls. However, these tests are occurring for all ttys, not
just ptys.

Implement flow control packet mode notifications in the pty driver.
Only the slave side implements the flow control handlers since
packet mode is asymmetric; the master pty receives notifications
for slave-side changes, but not vice versa.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 21:19:35 -07:00
Peter Hurley f9e053dcfc tty: Serialize tty flow control changes with flow_lock
Without serialization, the flow control state can become inverted
wrt. the actual hardware state. For example,

CPU 0                          | CPU 1
stop_tty()                     |
  lock ctrl_lock               |
  tty->stopped = 1             |
  unlock ctrl_lock             |
                               | start_tty()
                               |   lock ctrl_lock
                               |   tty->stopped = 0
                               |   unlock ctrl_lock
                               |   driver->start()
  driver->stop()               |

In this case, the flow control state now indicates the tty has
been started, but the actual hardware state has actually been stopped.

Introduce tty->flow_lock spinlock to serialize tty flow control changes.
Split out unlocked __start_tty()/__stop_tty() flavors for use by
ioctl(TCXONC) in follow-on patch.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 21:19:35 -07:00
Peter Hurley 938f7e13b5 serial: core: Use spin_lock_irq() in uart_set_termios()
uart_set_termios() is called with interrupts enabled; no need to
save and restore the interrupt state when taking the uart port lock.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 21:19:35 -07:00
Peter Hurley 8620d3e538 serial: bfin-uart: Fix auto CTS
Commit 64851636d5,
serial: bfin-uart: Remove ASYNC_CTS_FLOW flag for hardware automatic CTS,
open-codes uart_handle_cts_change() when CONFIG_SERIAL_BFIN_HARD_CTSRTS
to skip start and stop tx.

But the CTS interrupt handler _still_ calls uart_handle_cts_change();
only call uart_handle_cts_change() if !CONFIG_SERIAL_BFIN_HARD_CTSRTS.

cc: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 21:19:35 -07:00
Peter Hurley d01f4d181c serial: core: Privatize tty->hw_stopped
tty->hw_stopped is not used by the tty core and is thread-unsafe;
hw_stopped is a member of a bitfield whose fields are updated
non-atomically and no lock is suitable for serializing updates.

Replace serial core usage of tty->hw_stopped with uport->hw_stopped.
Use int storage which works around Alpha EV4/5 non-atomic byte storage,
since uart_port uses different locks to protect certain fields within the
structure.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 21:19:35 -07:00
Peter Hurley 299245a145 serial: core: Privatize modem status enable flags
The serial core uses the tty port flags, ASYNC_CTS_FLOW and
ASYNC_CD_CHECK, to track whether CTS and DCD changes should be
ignored or handled. However, the tty port flags are not safe for
atomic bit operations and no lock provides serialized updates.

Introduce the struct uart_port status field to track CTS and DCD
enable states, and serialize access with uart port lock. Substitute
uart_cts_enabled() helper for tty_port_cts_enabled().

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 21:19:35 -07:00
Peter Hurley 4d90bb147e serial: core: Document and assert lock requirements for irq helpers
The serial core provides two helper functions, uart_handle_dcd_change()
and uart_handle_cts_change(), for UART drivers to use at interrupt
time. The serial core expects the UART driver to hold the uart port lock
when calling these helpers to prevent state corruption.

If lockdep enabled, trigger a warning if the uart port lock is not held
when calling these helper functions.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 21:19:34 -07:00