In some conditions (echo or particular sequence of special
characters), on buffer push, the tty layer calls the write operation
while we are holding the spinlock. This means deadlock within the same
process on kernels version < 3.12. It seems not a problem on recent
kernel, but the patch still valid as locking optimization.
The protected variables by the spinlock are: xmit_buf, nb_bytes,
pointer_read and pointer_write. So, this patch reduces the locked area
in the IRQ handler only to these variables. Most of the code inside the
locked area in the IRQ handler is not protected elsewhere; it means
that it is not protected at all.
Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
Acked-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here's the big char/misc driver patches for 3.9-rc1.
Nothing major here, just lots of different driver updates (mei, hyperv, ipack,
extcon, vmci, etc.).
All of these 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 'char-misc-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver patches from Greg Kroah-Hartman:
"Here's the big char/misc driver patches for 3.9-rc1.
Nothing major here, just lots of different driver updates (mei,
hyperv, ipack, extcon, vmci, etc.).
All of these have been in the linux-next tree for a while."
* tag 'char-misc-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (209 commits)
w1: w1_therm: Add force-pullup option for "broken" sensors
w1: ds2482: Added 1-Wire pull-up support to the driver
vme: add missing put_device() after device_register() fails
extcon: max8997: Use workqueue to check cable state after completing boot of platform
extcon: max8997: Set default UART/USB path on probe
extcon: max8997: Consolidate duplicate code for checking ADC/CHG cable type
extcon: max8997: Set default of ADC debounce time during initialization
extcon: max8997: Remove duplicate code related to set H/W line path
extcon: max8997: Move defined constant to header file
extcon: max77693: Make max77693_extcon_cable static
extcon: max8997: Remove unreachable code
extcon: max8997: Make max8997_extcon_cable static
extcon: max77693: Remove unnecessary goto statement to improve readability
extcon: max77693: Convert to devm_input_allocate_device()
extcon: gpio: Rename filename of extcon-gpio.c according to kernel naming style
CREDITS: update email and address of Harald Hoyer
extcon: arizona: Use MICDET for final microphone identification
extcon: arizona: Always take the first HPDET reading as the final one
extcon: arizona: Clear _trig_sts bits after jack detection
extcon: arizona: Don't HPDET magic when headphones are enabled
...
Delete successive tests to the same location. The code tested the result
of a previous allocation, that itself was already tested. It is changed to
test the result of the most recent allocation.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@s exists@
local idexpression y;
expression x,e;
@@
*if ( \(x == NULL\|IS_ERR(x)\|y != 0\) )
{ ... when forall
return ...; }
... when != \(y = e\|y += e\|y -= e\|y |= e\|y &= e\|y++\|y--\|&y\)
when != \(XT_GETPAGE(...,y)\|WMI_CMD_BUF(...)\)
*if ( \(x == NULL\|IS_ERR(x)\|y != 0\) )
{ ... when forall
return ...; }
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The option allows you to remove TTY and compile without errors. This
saves space on systems that won't support TTY interfaces anyway.
bloat-o-meter output is below.
The bulk of this patch consists of Kconfig changes adding "depends on
TTY" to various serial devices and similar drivers that require the TTY
layer. Ideally, these dependencies would occur on a common intermediate
symbol such as SERIO, but most drivers "select SERIO" rather than
"depends on SERIO", and "select" does not respect dependencies.
bloat-o-meter output comparing our previous minimal to new minimal by
removing TTY. The list is filtered to not show removed entries with awk
'$3 != "-"' as the list was very long.
add/remove: 0/226 grow/shrink: 2/14 up/down: 6/-35356 (-35350)
function old new delta
chr_dev_init 166 170 +4
allow_signal 80 82 +2
static.__warned 143 142 -1
disallow_signal 63 62 -1
__set_special_pids 95 94 -1
unregister_console 126 121 -5
start_kernel 546 541 -5
register_console 593 588 -5
copy_from_user 45 40 -5
sys_setsid 128 120 -8
sys_vhangup 32 19 -13
do_exit 1543 1526 -17
bitmap_zero 60 40 -20
arch_local_irq_save 137 117 -20
release_task 674 652 -22
static.spin_unlock_irqrestore 308 260 -48
Signed-off-by: Joe Millenbach <jmillenbach@gmail.com>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There was a bug in the code when managing a GE IP-OCTAL-485 board. The RX would
be enabled but we have a wrong state in the rx_enable flag.
Then, if the user changes the terminal settings, RX would not be enabled again.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.
Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.
IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.
Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.
tty_insert_flip_char is the next one to proceed. This one is used all
over the code, so the patch is huge.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Added shutdown callback to disable RX and TX when there is no other client
accesing the device.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Thus, we don't enable RX when a termios setup has been called, as it could be
disabled previously.
As the control registers (Rx, Tx flags specifically) cannot be read from the
device, we keep this info in rx_enable.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The function is already called in ipoctal_irq_rx()
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We protect important data such as TX buffer pointer, nb_bytes counter and status
registers of the device, from accessing several times at the same time.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Due to the IRQ processing, we can generate another IRQ that can come before we
end the previous one, so we lost it. E.g. when transmitting a character.
To allow the processing in SMP machines, we ack the IRQ at the beginning of the
IRQ handler.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
RX is enabled when the tty port is open, so no need to do it in initialization
time: it can allow the device to receive characters but no TTY client is
listening to them.
It produced an infinite number of IRQ as RxFIFO is not read to clear that
IRQ in the device, so it is still pending.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Depending of the device, it disables the TX mode in different places when there
is no more data to transmit.
This patch reorder them and disable the TX mode in the same place.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In case of several characters present in RxFIFO, they will have the flag of the
previous one, no matter if the actual character was received properly or not.
This patch fixes this bug.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Trying to setup the pppd server to use ipoctal's serial ports, it says the ports
are busy the first time. If the operation is repeated, a kernel bug due to a
dereference of a NULL pointer appears.
Removing the one-access-only setup from the driver, removes this kernel bug.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It is an unsigned int so that check is pointless.
Signed-off-by: Alberto Garcia <agarcia@igalia.com>
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In order to transmit data, the driver enables Tx and sleeps until
*board_write is set to 1 by the interrupt handler.
It can happen, though, that the data is sent even before the process
is asleep. In this case *board_write must be set to 1 anyway,
otherwise we will be waiting for a condition that will never be true.
Signed-off-by: Alberto Garcia <agarcia@igalia.com>
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here's the big tty/serial tree set of changes for 3.8-rc1.
Contained in here is a bunch more reworks of the tty port layer from Jiri and
bugfixes from Alan, along with a number of other tty and serial driver updates
by the various driver authors.
Also, Jiri has been coerced^Wconvinced to be the co-maintainer of the TTY
layer, which is much appreciated by me.
All of these 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-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull TTY/Serial merge from Greg Kroah-Hartman:
"Here's the big tty/serial tree set of changes for 3.8-rc1.
Contained in here is a bunch more reworks of the tty port layer from
Jiri and bugfixes from Alan, along with a number of other tty and
serial driver updates by the various driver authors.
Also, Jiri has been coerced^Wconvinced to be the co-maintainer of the
TTY layer, which is much appreciated by me.
All of these have been in the linux-next tree for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
Fixed up some trivial conflicts in the staging tree, due to the fwserial
driver having come in both ways (but fixed up a bit in the serial tree),
and the ioctl handling in the dgrp driver having been done slightly
differently (staging tree got that one right, and removed both
TIOCGSOFTCAR and TIOCSSOFTCAR).
* tag 'tty-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (146 commits)
staging: sb105x: fix potential NULL pointer dereference in mp_chars_in_buffer()
staging/fwserial: Remove superfluous free
staging/fwserial: Use WARN_ONCE when port table is corrupted
staging/fwserial: Destruct embedded tty_port on teardown
staging/fwserial: Fix build breakage when !CONFIG_BUG
staging: fwserial: Add TTY-over-Firewire serial driver
drivers/tty/serial/serial_core.c: clean up HIGH_BITS_OFFSET usage
staging: dgrp: dgrp_tty.c: Audit the return values of get/put_user()
staging: dgrp: dgrp_tty.c: Remove the TIOCSSOFTCAR ioctl handler from dgrp driver
serial: ifx6x60: Add modem power off function in the platform reboot process
serial: mxs-auart: unmap the scatter list before we copy the data
serial: mxs-auart: disable the Receive Timeout Interrupt when DMA is enabled
serial: max310x: Setup missing "can_sleep" field for GPIO
tty/serial: fix ifx6x60.c declaration warning
serial: samsung: add devicetree properties for non-Exynos SoCs
serial: samsung: fix potential soft lockup during uart write
tty: vt: Remove redundant null check before kfree.
tty/8250 Add check for pci_ioremap_bar failure
tty/8250 Add support for Commtech's Fastcom Async-335 and Fastcom Async-PCIe cards
tty/8250 Add XR17D15x devices to the exar_handle_irq override
...
Its contents are merged into ipack.h. So this file is not needed.
Doing that, it simplifies the ipack-related driver development.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move ipack header files to include/linux/ directory where they belong.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ipack subsystem is cleaned up enough to now move out of the staging
tree, and into drivers/ipack.
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Federico Vaga