Commit Graph

121 Commits

Author SHA1 Message Date
Rodolfo Giometti dc77f161aa serial 8250: enable PPS support
Automagically function serial8250_enable_ms() is called when PPS ldisc
is selected.

Signed-off-by: Rodolfo Giometti <giometti@linux.it>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg KH <greg@kroah.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:43 -08:00
Shmulik Ladkani b5d228cc4f serial: copy UART properties of UPF_FIXED_TYPE ports provisioned using early_serial_setup
Augment the UPF_FIXED_TYPE logic, which currently applies to UART ports
provisioned using platform_device_register.

The suggested patch applies same logic into 'serial8250_register_ports',
making UART ports provisioned using early_serial_setup inherit their
properties from the uart_config entry.

Signed-off-by: Shmulik Ladkani <shmulik@jungo.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-02 14:43:07 -08:00
Manuel Lauss b2b13cdfd0 SERIAL 8250: Fixes for Alchemy UARTs.
Limit the amount of address space claimed for Alchemy serial ports to
0x1000.  On the Au1300, ports are only 0x1000 apart, and the registers
only extend to 0x110 at most on all supported alchemy models.

On the Au1300 the autodetect logic no longer works and this makes it
necessary to specify the port type through platform data.  Because of
this the MSR quirk needs to be moved outside the autoconfig() function
which will no longer be called when UPF_FIXED_TYPE is specified.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-02-27 12:52:57 +01:00
Dick Hollenbeck bca476139d serial: 8250: add serial transmitter fully empty test
When controlling an industrial radio modem it can be necessary to
manipulate the handshake lines in order to control the radio modem's
transmitter, from userspace.

The transmitter should not be turned off before all characters have been
transmitted.  serial8250_tx_empty() was reporting that all characters were
transmitted before they actually were.

===

Discovered in parallel with more testing and analysis by Kees Schoenmakers
as follows:

I ran into an NetMos 9835 serial pci board which behaves a little
different than the standard.  This type of expansion board is very common.

"Standard" 8250 compatible devices clear the 'UART_LST_TEMT" bit together
with the "UART_LSR_THRE" bit when writing data to the device.

The NetMos device does it slightly different

I believe that the TEMT bit is coupled to the shift register.  The problem
is that after writing data to the device and very quickly after that one
does call serial8250_tx_empty, it returns the wrong information.

My patch makes the test more robust (and solves the problem) and it does
not affect the already correct devices.

Alan:

  We may yet need to quirk this but now we know which chips we have a
  way to do that should we find this breaks some other 8250 clone with
  dodgy THRE.

Signed-off-by: Dick Hollenbeck <dick@softplc.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Kees Schoenmakers <k.schoenmakers@sigmae.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-02-16 15:55:51 -08:00
Ian Jackson 68cb4f8e24 Serial: Do not read IIR in serial8250_start_tx when UART_BUG_TXEN
Do not read IIR in serial8250_start_tx when UART_BUG_TXEN

Reading the IIR clears some oustanding interrupts so it is not safe.
Instead, simply transmit immediately if the buffer is empty without
regard to IIR.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Jiri Kosina <jkosina@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11 15:18:05 -08:00
André Goddard Rosa 4c0ebb8057 serial, 8250: calculate irqflags bitmask before loop
Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11 15:18:04 -08:00
Lennert Buytenhek 80647b959f serial: fix printk format specifiers for struct uart_port::iobase
struct uart_port::iobase is unsigned long, so use %lx as printk format
specifier.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-11-12 07:25:57 -08:00
Chuck Ebbert d41a4b515e serial: add parameter to force skipping the test for the TXEN bug
Allow users to force skipping the TXEN test at init time. Applies
to all serial ports. Intended for debugging only.

There is a blacklist for devices where we need to skip the test but the
list is not complete.  This lets users force skipping the test so we can
determine if they need to be added to the list.

Some HP machines with weird serial consoles have this problem and there
may be more.

Signed-off-by: Chuck Ebbert <cebbert@redhat.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:16 -07:00
Alan Cox bdc04e3174 serial: move delta_msr_wait into the tty_port
This is used by various drivers not just serial and can be extracted
as commonality

Signed-off-by: Alan Cox <alan@linux.intel.com>
2009-09-19 13:13:31 -07:00
Alan Cox ebd2c8f6d2 serial: kill off uart_info
We moved this into uart_state, now move the fields out of the separate
structure and kill it off.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:28 -07:00
Anton Vorontsov 24d481ecae 8250: Now honours baud rate lower bounds
A platform clock drives 8250 ports in most SOC systems, the clock
might run at high frequencies, and so it's not always possible to
downscale uart clock to a desired value.

Currently the 8250 uart driver accepts not supported baud rates, and
what is worse, it is doing this silently, and then passes not accepted
values to a new termios, so userspace has no chance to catch this kind
of errors (userspace verifies that settings were accepted by reading
back and comparing the settings).

This patch fixes the issue by passing minimum baud rate to the
uart_get_baud_rate() call, the call should take care of all bounds,
so userspace should now report:

  # stty -F /dev/ttyS0 speed 300
  115200
  stty: /dev/ttyS0: unable to perform all requested operations

p.s. uart_get_baud_rate() falls back to 9600, which still might be too
     low for some 10 GHz platforms, but that's a separate issue, and
     we can wait with fixing this till we find such a platform.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:20 -07:00
Vikram Pandita 1c2f04937b serial: 8250: add IRQ trigger support
There is currently no provision for passing IRQ trigger flags for
serial IRQs with triggering requirements (such as GPIO IRQs)

This patch adds irqflags to plat_serial8250_port that can be passed
from board file to reqest_irq() of 8250 driver

Changes are backward compatible with boards passing UPF_SHARE_IRQ flag

Tested on Zoom2 board that has IRQF_TRIGGER_RISING requirement for 8250 irq

[Moved new flag to end to fix bugs in the original with the old_serial array
	-- Alan]

Signed-off-by: Vikram Pandita <vikram.pandita@ti.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:19 -07:00
Florian Fainelli 08e0992f60 serial: add support for the TI AR7 internal UART
This patch adds support for the TI AR7 internal UART.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:03 -07:00
Alan Cox b8e7e40abe 8250: Fix oops from setserial
If you setserial a port which has never been initialised we change the type
but don't update the I/O method pointers. The same problem is true if you
change the io type of a port - but nobody ever does that so nobody noticed!

Remember the old type and when attaching if the type has changed reload the
port accessor pointers. We can't do it blindly as some 8250 drivers load custom
accessors and we must not stomp those.

Tested-by: Victor Seryodkin <vvscore@gmail.com>
Closes-bug: #13367
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-29 08:42:38 -07:00
Mauro Carvalho Chehab b6adea334c 8250: fix boot hang with serial console when using with Serial Over Lan port
Intel 8257x Ethernet boards have a feature called Serial Over Lan.

This feature works by emulating a serial port, and it is detected by
kernel as a normal 8250 port.  However, this emulation is not perfect, as
also noticed on changeset 7500b1f602.

Before this patch, the kernel were trying to check if the serial TX is
capable of work using IRQ's.

This were done with a code similar this:

        serial_outp(up, UART_IER, UART_IER_THRI);
        lsr = serial_in(up, UART_LSR);
        iir = serial_in(up, UART_IIR);
        serial_outp(up, UART_IER, 0);

        if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT)
		up->bugs |= UART_BUG_TXEN;

This works fine for other 8250 ports, but, on 8250-emulated SoL port, the
chip is a little lazy to down UART_IIR_NO_INT at UART_IIR register.

Due to that, UART_BUG_TXEN is sometimes enabled.  However, as TX IRQ keeps
working, and the TX polling is now enabled, the driver miss-interprets the
IRQ received later, hanging up the machine until a key is pressed at the
serial console.

This is the 6 version of this patch.  Previous versions were trying to
introduce a large enough delay between serial_outp and serial_in(up,
UART_IIR), but not taking forever.  However, the needed delay couldn't be
safely determined.

At the experimental tests, a delay of 1us solves most of the cases, but
still hangs sometimes.  Increasing the delay to 5us was better, but still
doesn't solve.  A very high delay of 50 ms seemed to work every time.

However, poking around with delays and pray for it to be enough doesn't
seem to be a good approach, even for a quirk.

So, instead of playing with random large arbitrary delays, let's just
disable UART_BUG_TXEN for all SoL ports.

[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-20 17:57:50 -08:00
Helge Deller 125c97d8a5 fix early_serial_setup() regression
Commit b430428a18 ("8250: Don't clobber
spinlocks.") introduced a regression on the parisc architecture, which
broke the handover to the serial port at boottime.

early_serial_setup() was changed to only copy a subset of the uart_port
fields, and sadly the "type" and "line" fields were forgotten and thus
the serial port was not initialized and could not be used for a
handover.  This patch fixes this by copying the missing fields.

As this change to early_serial_setup() doesn't need an initialized
spinlock in the uart_port struct any longer, we can drop the spinlock
initialization in the superio driver.

Cc: David Daney <ddaney@caviumnetworks.com>
Cc: Tomaso Paoletti <tpaoletti@caviumnetworks.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-13 14:03:43 -08:00
Paul Bolle f1fb9bb859 trivial: Add a space (and a comma) to a printk in 8250 driver
Commit d87a6d9 ("drivers/serial/: remove CVS keywords") removed one
space too many in the printk in serial8250_init(). Put it back in (and
add a comma for clarity).

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-01-06 11:28:09 +01:00
David Daney 6b06f19151 Serial: UART driver changes for Cavium OCTEON.
Cavium UART implementation is not covered by existing uart_configS.
Define a new uart_config (PORT_OCTEON) which is specified by OCTEON
platform device registration code.

Signed-off-by: Tomaso Paoletti <tpaoletti@caviumnetworks.com>
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02 10:19:43 -08:00
David Daney 8e23fcc89c Serial: Allow port type to be specified when calling serial8250_register_port.
Add flag value UPF_FIXED_TYPE which specifies that the UART type is
known and should not be probed.  For this case the UARTs properties
are just copied out of the uart_config entry.

This allows us to keep SOC specific 8250 probe code out of 8250.c.  In
this case we know the serial hardware will not be changing as it is on
the same silicon as the CPU, and we can specify it with certainty in
the board/cpu setup code.

The alternative is to load up 8250.c with a bunch of OCTEON specific
special cases in the probing code.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02 10:19:43 -08:00
David Daney 7d6a07d123 8250: Serial driver changes to support future Cavium OCTEON serial patches.
In order to use Cavium OCTEON specific serial i/o drivers, we first
patch the 8250 driver to use replaceable I/O functions.  Compatible
I/O functions are added for existing iotypeS.

An added benefit of this change is that it makes it easy to factor
some of the existing special cases out to board/SOC specific support
code.

The alternative is to load up 8250.c with a bunch of OCTEON specific
iotype code and bug work-arounds.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Tomaso Paoletti <tpaoletti@caviumnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02 10:19:43 -08:00
David Daney b430428a18 8250: Don't clobber spinlocks.
In serial8250_isa_init_ports(), the port's lock is initialized.  We
should not overwrite it.  In early_serial_setup(), only copy in the
fields we need.  Since the early console code only uses a subset of
the fields, these are sufficient.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Tomaso Paoletti <tpaoletti@caviumnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02 10:19:42 -08:00
Linus Torvalds 9301975ec2 Merge branch 'genirq-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
This merges branches irq/genirq, irq/sparseirq-v4, timers/hpet-percpu
and x86/uv.

The sparseirq branch is just preliminary groundwork: no sparse IRQs are
actually implemented by this tree anymore - just the new APIs are added
while keeping the old way intact as well (the new APIs map 1:1 to
irq_desc[]).  The 'real' sparse IRQ support will then be a relatively
small patch ontop of this - with a v2.6.29 merge target.

* 'genirq-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (178 commits)
  genirq: improve include files
  intr_remapping: fix typo
  io_apic: make irq_mis_count available on 64-bit too
  genirq: fix name space collisions of nr_irqs in arch/*
  genirq: fix name space collision of nr_irqs in autoprobe.c
  genirq: use iterators for irq_desc loops
  proc: fixup irq iterator
  genirq: add reverse iterator for irq_desc
  x86: move ack_bad_irq() to irq.c
  x86: unify show_interrupts() and proc helpers
  x86: cleanup show_interrupts
  genirq: cleanup the sparseirq modifications
  genirq: remove artifacts from sparseirq removal
  genirq: revert dynarray
  genirq: remove irq_to_desc_alloc
  genirq: remove sparse irq code
  genirq: use inline function for irq_to_desc
  genirq: consolidate nr_irqs and for_each_irq_desc()
  x86: remove sparse irq from Kconfig
  genirq: define nr_irqs for architectures with GENERIC_HARDIRQS=n
  ...
2008-10-20 13:23:01 -07:00
Linus Torvalds 8ef50901d3 Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (51 commits)
  [ARM] 5308/1: Fix Viper ISA IRQ handling
  [ARM] 5307/1: pxa: fix CM-X2XX PCMCIA build error
  [ARM] 5306/1: pxa: fix build error on CM-X270
  [ARM] 5302/1: ARM: OMAP: Revert omap3 WDT changes to avoid merge conflict
  [ARM] 5305/1: ARM: OMAP: Fix compile of McBSP by removing unnecessary check
  [ARM] 5301/1: ARM: OMAP: Add missing irq defines
  ARM: OMAP3: Add default kernel config for OMAP LDP
  ARM: OMAP3: Add basic board support for OMAP LDP
  ARM: OMAP3: Defconfig for the Gumstix Overo board (rev 3)
  ARM: OMAP3: Add support for the Gumstix Overo board (rev 3)
  ARM: OMAP3: Add Beagle defconfig
  ARM: OMAP3: Add minimal Beagle board support
  ARM: OMAP3: Add minimal omap3430 support
  ARM: OMAP2: Fix sparse, checkpatch warnings in OMAP2/3 IRQ code
  ARM: OMAP: Fixes to omap_mcbsp_request function
  ARM: OMAP: Add support for OMAP2430 in McBSP
  ARM: OMAP: Add support for McBSP devices 3 - 5 on 34xx
  ARM: OMAP: Allocate McBSP devices dynamically
  Fix sections for omap-mcbsp platform driver
  [ARM] S3C24XX: Additional include moves
  ...
2008-10-16 11:25:32 -07:00
Yinghai Lu a62c413373 drivers/serial: use nr_irqs
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:06 +02:00
Alan Cox 25db8ad5c5 serial, 8250: remove NR_IRQ usage
Works on my test box with a quick test.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:02 +02:00
Russell King 2502991560 Merge branch 'fixes' into for-linus
Conflicts:

	arch/arm/mach-versatile/core.c
2008-10-15 23:16:07 +01:00
Alan Cox 4aba41ea8b 8250: Fix lock warning (and possible crash)
Splitting the 8250 code back up to avoid a clash with the NR_IRQS removal
patch introduced a last minute bug. Put back the additional needed lines
for the old lock init

Signed-off-by: Alan Cox <alan@redhat.com>
[ Ingo also reports that this can cause a spontaneous reboot crash with
  certain configs, and sends in an identical patch ]
Tested-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-14 10:03:33 -07:00
David S. Miller 8440838bc5 serial: fix device name reporting when minor space is shared between drivers
The multiple drivers share the minor space occupied by a particular major
number, the actual index within the device name's space is indicated by
the tty_driver->name_base + uart_port->line

Another usable formula is (uart_driver->minor - MINOR_BASE) + port->line

Use those to print the device names properly in such situations in
serial_core.c and 8250.c

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 09:51:44 -07:00
David Miller b70ac77185 serial: allow 8250 to be used on sparc
This requires three changes:

1) Remove !SPARC restriction in Kconfig.

2) Move Sparc specific serial drivers before 8250, so that serial
   console devices don't change names on us, even if 8250 finds
   devices.

3) Since the Sparc specific serial drivers try to use the
   same major/minor device namespace as 8250, some coordination
   is necessary.  Use the sunserial_*() layer routines to allocate
   minor number space within TTY_MAJOR when CONFIG_SPARC.

   This has no effect on other platforms.

Thanks to Josip Rodin for bringing up this issue and testing
plus debugging various revisions of this patch.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 09:51:40 -07:00
Will Newton b5d674abcf 8250: remove a few inlines of dubious value
Remove some inlines from various functions that are called once, are too
big to inline, or are called only from slow path code.  This saves around
300 bytes of code for me.

Signed-off-by: Will Newton <will.newton@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 09:51:40 -07:00
Russell King f2eda27d1c [SERIAL] 8250: serial8250_port_size() - omap ports are larger
A function to contain common code for the size of the resource we
need to allocate or free.  OMAP ports need 22 bytes rather than
the standard 8 bytes.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-05 17:02:28 +01:00
Russell King 5668545a08 [ARM] omap: improve is_omap_port()
Make is_omap_port() take the uart_8250_port structure so it can do
whatever test it desires.  Convert the test to compare the physical
addresses rather than virtual addresses.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-05 17:02:28 +01:00
Will Newton 363f66fe06 8250: improve workaround for UARTs that don't re-assert THRE correctly
Recent changes to tighten the check for UARTs that don't correctly
re-assert THRE (01c194d9278efc15d4785ff205643e9c0bdcef53: "serial 8250:
tighten test for using backup timer") caused problems when such a UART was
opened for the second time - the bug could only successfully be detected
at first initialization.  For users of this version of this particular
UART IP it is fatal.

This patch stores the information about the bug in the bugs field of the
port structure when the port is first started up so subsequent opens can
check this bit even if the test for the bug fails.

David Brownell: "My own exposure to this is that the UART on DaVinci
hardware, which TI allegedly derived from its original 16550 logic, has
periodically gone from working to unusable with the mainline 8250.c ...
and back and forth a bunch.  Currently it's "unusable", a regression from
some previous versions.  With this patch from Will, it's usable."

Signed-off-by: Will Newton <will.newton@gmail.com>
Acked-by: Alex Williamson <alex.williamson@hp.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Brownell <david-b@pacbell.net>
Cc: <stable@kernel.org>		[2.6.26.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02 19:21:38 -07:00
Borislav Petkov c389d27b5e 8250.c: port.lock is irq-safe
serial8250_startup() doesn't disable interrupts while taking the &up->port.lock
which might race against the interrupt handler serial8250_interrupt(), which
when entered, will deadlock waiting for the lock to be released.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30 09:41:45 -07:00
Aristeu Rozanski 7500b1f602 8250: fix break handling for Intel 82571
Intel 82571 has a "Serial Over LAN" feature that doesn't properly
implements the receiving of break characters.  When a break is received,
it doesn't set UART_LSR_DR and unless another character is received, the
break won't be received by the application.

Signed-off-by: Aristeu Rozanski <arozansk@redhat.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:29 -07:00
Anton Vorontsov 768aec0b5b serial: 8250: fix shared interrupts issues with SMP and RT kernels
With SMP kernels _irqsave spinlock disables only local interrupts, while
the shared serial interrupt could be assigned to the CPU that is not
currently starting up the serial port.

This might cause issues because serial8250_startup() routine issues
IRQ-triggering operations before registering the port in the IRQ chain
(though, this is fine to do and done explicitly because we don't want to
process any interrupts on the port startup).

With RT kernels and preemptable hardirqs, _irqsave spinlock does not
disable local hardirqs, and the bug could be reproduced much easily:

$ cat /dev/ttyS0 &
$ cat /dev/ttyS1
irq 42: nobody cared (try booting with the "irqpoll" option)
Call Trace:
[C0475EB0] [C0008A98] show_stack+0x4c/0x1ac (unreliable)
[C0475EF0] [C004BBD4] __report_bad_irq+0x34/0xb8
[C0475F10] [C004BD38] note_interrupt+0xe0/0x308
[C0475F50] [C004B09C] thread_simple_irq+0xdc/0x104
[C0475F70] [C004B3FC] do_irqd+0x338/0x3c8
[C0475FC0] [C00398E0] kthread+0xf8/0x100
[C0475FF0] [C0011FE0] original_kernel_thread+0x44/0x60
handlers:
[<c02112c4>] (serial8250_interrupt+0x0/0x138)
Disabling IRQ #42

After this, all serial ports on the given IRQ are non-functional.

To fix the issue we should explicitly disable shared IRQ before
issuing any IRQ-triggering operations.

I also changed spin_lock_irqsave to the ordinary spin_lock, since it
seems to be safe: chain does not contain new port (yet), thus nobody
will interfere us from the ISRs.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-22 13:03:28 -07:00
Alan Cox df4f4dd429 serial: use tty_port
Switch the serial_core based drivers to use the new tty_port structure.
We can't quite use all of it yet because of the dynamically allocated
extras in the serial_core layer.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-20 17:12:35 -07:00
Adrian Bunk d87a6d951c drivers/serial/: remove CVS keywords
This patch removes CVS keywords that weren't updated for a long time in
comments, printk's and MODULE_DESCRIPTION's (no printk's or
MODULE_DESCRIPTION's are completely removed).

While doing this I also found and fixed a missing \n in a printk
in m32r_sio.c

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-20 17:12:35 -07:00
Eric W. Biederman 05d81d2222 serial8250: sanity check nr_uarts on all paths.
I had 8250.nr_uarts=16 in the boot line of a test kernel and I had a weird
mysterious crash in sysfs.  After taking an in-depth look I realized that
CONFIG_SERIAL_8250_NR_UARTS was set to 4 and I was walking off the end of
the serial8250_ports array.

Ouch!!!

Don't let this happen to someone else.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Alan Cox <alan@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-12 14:33:41 -07:00
Bryan Wu a4ed1e41a7 8250 Serial Driver: revert extra IRQ flag definition patch
As Russell pointed out, original patch will break some serial configurations
because of the dependency of the <asm/serial.h> header file.

Revert it first and try to find out other solution later

Cc: Javier Herrero <jherrero@hvsistemas.es>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Russell King <rmk+lkml@arm.linux.org.uk>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
2008-05-31 16:10:04 +08:00
Javier Herrero b4aa54d951 8250 Serial Driver: Added support for 8250-class UARTs in HV Sistemas H8606 board
Added support for 8250-class UARTs in HV Sistemas H8606 board,
modification in 8250.c driver for correct compilation with Blackfin

Besides, I think that there is more people using 8250-class UARTs
with a different hardware than the H8606 board. This code can be shared
by them.

Signed-off-by: Javier Herrero <jherrero@hvsistemas.es>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
2008-05-17 18:21:42 +08:00
Alan Cox 6f441fe998 8250: switch 8250 drivers to use _nocache ioremaps
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01 08:04:00 -07:00
Alex Williamson 01c194d927 serial 8250: tighten test for using backup timer
Thomas Koeller had reported an issue where a device that had been making use
of the UART_BUG_TXEN code in the 8250 driver was mistakenly being caught by
the backup timer test, causing the device to work improperly.

To fix this, tighten the test requirements to enable the backup timer
workaround.

The backup timer is really meant to catch UARTs that don't re-assert the THRE
interrupt.  The expectation is that they do initially assert THRE.  This patch
clarifies the test.

Signed-off-by: Alex Williamson <alex.williamson@hp.com>
Cc: Thomas Koeller <thomas@koeller.dyndns.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:30 -07:00
Alan Cox e991a2bd4f Fix tty speed handling on 8250
We try and write the correct speed back but the serial midlayer already
mangles the speed on us and that means if we request B0 we report back B9600
when we should not.  For now we'll hack around this in the drivers and serial
code, pending a better long term solution.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:29 -07:00
Jason Wessel f2d937f3bf consoles: polling support, kgdboc
polled console handling support, to access a console in an irq-less
way while in debug or irq context.

absolutely zero impact as long as CONFIG_CONSOLE_POLL is disabled.
(which is the default)

[ jan.kiszka@siemens.com: lots of cleanups ]
[ mingo@elte.hu: redesign, splitups, cleanups. ]

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-17 20:05:37 +02:00
Alan Cox b4c502a709 8250: enable rate reporting via termios
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox 6f803cd08f serial8250: coding style
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox 3e8d4e2075 serial: Coding style
Coding style tweaks and printk levels.

Signed-off-by: Alan Cox <alan@redhat.com>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:10 -08:00
Will Newton 74a1974172 8250.c: support specifying DW APB UARTs in device platform_data
Allow the private_data field to be specified in platform_data for the
standard 8250/16550 UART.  This field is used by DW APB type UARTs and
without this patch it's only possible to set this field when registering
the port by hand.  If private_data is not set then the driver will
potentially oops with a NULL pointer dereference.

Signed-off-by: Will Newton <will.newton@gmail.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:09 -08:00
Corey Minyard ad4c2aa635 Serial 8250: handle saving the clear-on-read bits from the LSR and MSR
Reading the LSR clears the break, parity, frame error, and overrun bits in
the 8250 chip, but these are not being saved in all places that read the
LSR.  Same goes for the MSR delta bits.  Save the LSR bits off whenever the
lsr is read so they can be handled later in the receive routine.  Save the
MSR bits to be handled in the modem status routine.

Also, clear the stored bits and clear the interrupt registers before
enabling interrupts, to avoid handling old values of the stored bits in the
interrupt routines.

[akpm@linux-foundation.org: clean up pre-existing code]
Signed-off-by: Corey Minyard <minyard@acm.org>
Cc: Russell King <rmk+lkml@arm.linux.org.uk>
Cc: Yinghai Lu <yinghai.lu@sun.com>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-22 19:52:44 -07:00