Commit graph

3,514 commits

Author SHA1 Message Date
Soren Brinkmann
d3641f64bc tty: xuartps: Fix build error due to missing forward declaration
If CONFIG_PM_SLEEP is enabled and CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
is not, a forward declaration of the uart_driver struct is not
included, leading to a build error due to an undeclared variable.
Fixing this by moving the definition of the struct uart_driver before
the definition of the suspend/resume callbacks.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29 09:26:11 -07:00
Soren Brinkmann
d54b181ea6 tty: xuartps: Fix "may be used uninitialized" build warning
Initialize varibles for which a 'may be used uninitalized' warning is
issued.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29 09:26:11 -07:00
Hendrik Brueckner
ac526f42ab tty/hvc_iucv: remove redundant NULL check
Make smatch happy and remove this warning:

drivers/tty/hvc/hvc_iucv.c:1320 hvc_iucv_init() info: redundant null check on
hvc_iucv_filter calling kfree()

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-28 08:36:29 +01:00
Vinod Koul
0b3d7d39f5 serial: sh: use DMA_COMPLETE for dma completion status
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-10-25 11:16:19 +05:30
Thierry Reding
f7578496a6 of/irq: Use irq_of_parse_and_map()
Replace some instances of of_irq_map_one()/irq_create_of_mapping() and
of_irq_to_resource() by the simpler equivalent irq_of_parse_and_map().

Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
[grant.likely: resolved conflicts with core code renames]
Signed-off-by: Grant Likely <grant.likely@linaro.org>
2013-10-24 11:50:35 +01:00
Angelo Butti
9434147520 serial: 8250_pci: add Pericom PCIe Serial board Support (12d8:7952/4/8) - Chip PI7C9X7952/4/8
Signed-off-by: Angelo Butti <buttiangelo@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:51:17 -07:00
Soren Brinkmann
37cd940b20 tty: xuartps: Update copyright information
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:38 -07:00
Soren Brinkmann
4b47d9aa1e tty: xuartps: Implement suspend/resume callbacks
Implement suspend and resume callbacks in order to support system
suspend/hibernation.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:38 -07:00
Soren Brinkmann
c4b0510cc1 tty: xuartps: Dynamically adjust to input frequency changes
Add a clock notifier to dynamically handle frequency changes of the
input clock by reprogramming the UART in order to keep the baud rate
constant.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:38 -07:00
Soren Brinkmann
e6b39bfd0d tty: xuartps: Updating set_baud_rate()
The original algorithm to find the best baud rate dividers does not necessarily
find the best set of dividers. And in the worst case may even write illegal
values to the hardware.
The new function should make better use of the hardware capabilities and be able
to provide valid settings for a wider range of baud rates and also input clocks.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:38 -07:00
Lars-Peter Clausen
d3755f5e6c tty: xuartps: Force enable the UART in xuartps_console_write
It is possible that under certain circumstances xuartps_console_write is entered
while the UART disabled. When this happens the code will busy loop in
xuartps_console_putchar, since the character is never written and the TXEMPTY
flag is never set. The result is a system lockup. This patch force enables the
UART for the duration of xuartps_console_write to avoid this.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: John Linn <john.linn@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:38 -07:00
Suneel
85baf542d5 tty: xuartps: support 64 byte FIFO size
Changes to use the 64 byte FIFO depth and fix the issue
by clearing the txempty interrupt in isr status for tx
after filling in data in start_tx function

Signed-off-by: Suneel Garapati <suneelg@xilinx.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:37 -07:00
Vlad Lungu
6ee04c6c54 tty: xuartps: Add polled mode support for xuartps
This allows KDB/KGDB to run.

Signed-off-by: Vlad Lungu <vlad.lungu@windriver.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:37 -07:00
Vlad Lungu
0c0c47bc40 tty: xuartps: Implement BREAK detection, add SYSRQ support
The Cadence UART does not do break detection, even if the
datasheet says it does. This patch adds break detection in
software (tested in 8N1 mode only) and enables SYSRQ,
allowing for Break-g to enter KDB and all the other goodies.

Signed-off-by: Vlad Lungu <vlad.lungu@windriver.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:37 -07:00
Soren Brinkmann
c03cae1791 tty: xuartps: Use devm_kzalloc
Use the device managed interface for memory allocation, simplifying
error paths.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:37 -07:00
Soren Brinkmann
991fc25936 tty: xuartps: Use devm_clk_get()
Use the device managed interface for clocks, simplifying error paths.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 19:47:37 -07:00
Nicolas Ferre
731d9cae02 tty/serial: at91: add a fallback option to determine uart/usart property
On older SoC, the "name" field is not filled in the register map.
Fix the way to figure out if the serial port is an uart or an usart for these
older products (with corresponding properties).

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-17 13:31:19 -07:00
Nicolas Ferre
892db58bd1 tty/serial: at91: fix uart/usart selection for older products
Since commit 055560b04a (serial: at91:
distinguish usart and uart) the older products which do not have a
name field in their register map are unable to use their serial output.
As the main console output is usually the serial interface (aka DBGU) it
is pretty unfortunate.
So, instead of failing during probe() we just silently configure the serial
peripheral as an uart. It allows us to use these serial outputs.
The proper solution is proposed in another patch.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-17 13:30:14 -07:00
Nicolas Ferre
6e757ad2c9 tty/serial: at91: fix uart/usart selection for older products
Since commit 055560b04a (serial: at91:
distinguish usart and uart) the older products which do not have a
name field in their register map are unable to use their serial output.
As the main console output is usually the serial interface (aka DBGU) it
is pretty unfortunate.
So, instead of failing during probe() we just silently configure the serial
peripheral as an uart. It allows us to use these serial outputs.
The proper solution is proposed in another patch.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-17 13:27:24 -07:00
Greg Kroah-Hartman
2c62a3c899 serial: 8250_pci: add support for Fintek 4, 8, and 12 port cards
This adds support for Fintek's 4, 8, and 12 port PCIE serial cards.

Thanks to Fintek for the sample devices, and the spec needed in order to
implement this.

Cc: Amanda Ying <amanda_ying@fintek.com.tw>
Cc: Felix Shih <felix_shih@fintek.com.tw>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-17 13:21:59 -07:00
Huang Shijie
7cb92fd2a0 serial: imx: optimization: remove the workqueues for DMA
I worried that the delay of the sdma_run_channel0() maybe too long for
interrupt context, so I added the workqueues for RX/TX DMA.

But tested with bluetooth device, I find that the delay of sdma_run_channel0()
is about 8us (tested in imx6dl sabreauto board). I think the delay
is acceptable.

This patch removes the RX/TX workqueues for DMA, it makes the
code more clear.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 18:25:30 -07:00
Roel Kluin
d969de8d83 serial: vt8500: add missing braces
Due to missing braces on an if statement, in presence of a device_node a
port was always assigned -1, regardless of any alias entries in the
device tree. Conversely, if device_node was NULL, an unitialized port
ended up being used.

This patch adds the missing braces, fixing the issues.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Tony Prisk <linux@prisktech.co.nz>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:22:16 -07:00
Huang Shijie
f0ef8834b2 serial: imx: use the dmaengine_tx_status
Use the dmaengine_tx_status to simplify the code, do not change any logic.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:19:55 -07:00
Huang Shijie
947c74eba8 serial: imx: fix the wrong number of scatterlist entries when xmit->head is 0
When the (xmit->tail > xmit->head) is true and the xmit->head is 0,
we only need one DMA scatterlist in actually. Current code uses two DMA
scatterlists in this case, this is obviously wrong.

This patch fixes it.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:19:54 -07:00
Huang Shijie
1ce43e58d4 serial: imx: check the DMA for imx_tx_empty
Assume the following situation:

  If the DMA is enabled, and the a TX DMA operation is working,
But we have not issued the TX DMA operation (or we have issued the
TX DMA operation with dma_async_issue_pending(), but the DMA has not
started to move the data from the memory to the TXFIFO).

At this time, we may get the wrong status of the transmitter when we
call the imx_tx_empty. In such situation, only check the USR2_TXDC
does not enough for us.

This patch checks the DMA's situation, and return 0 when the TX DMA is
working.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:19:54 -07:00
Huang Shijie
eb56b7edae serial: imx: implement the flush_buffer hook
The current driver does not implement the flush_buffer hook for
uart_ops. When we enable the DMA for the driver, and test it with Bluetooth,
we may meet the following bug for TX:

    [1] User application may call the flush operation at any time.
        The uart_flush_buffer() calls the uart_circ_clear() to set
        the xmit->head and xmit->tail with 0.

    [2] The TX DMA callback can be called at any time too.
        The dma_tx_call() will update the xmit->tail.

    If [2] occurs just after the [1], we will get the wrong xmit->tail.

This patch implements the flush_buffer hook to fix this issue.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:19:54 -07:00
Linus Walleij
3592501054 serial: pch_uart: remove reference to .set_wake()
This callback is gone and not coming back, so will not be
supported later.

Cc: Johan Hovold <jhovold@gmail.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:16:19 -07:00
Linus Walleij
c38c4454d8 serial: mpc52xx: remove reference to .set_wake()
This callback is gone and not coming back, so will not be
supported later.

Cc: Gerhard Sittig <gsi@denx.de>
Cc: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:16:19 -07:00
Linus Walleij
adedb75072 serial: sa1100: delete .set_wake callback
This callback is unused by the serial core since pre-git days
and is not coming back. Delete it. Enabling wakeup on the
SA1100 platforms should be done in the suspend() callback
so the platform hook is left in the serial port struct for
later enablement.

Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:16:18 -07:00
Linus Walleij
e701bcadb2 serial: omap: delete .set_wake callback
This callback is unused by the serial core since pre-git days
and is not coming back. Delete it. Enabling wakeup on the
OMAP serial driver is done through other runpaths these days.

Cc: Tony Lindgren <tony@atomide.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:16:18 -07:00
Roel Kluin
c476f6584b tty: incorrect test of echo_buf() result for ECHO_OP_START
test echo_buf() result for ECHO_OP_START

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:12:13 -07:00
Joe Perches
fc811472c2 tty: Remove unnecessary semicolons
These aren't necessary after switch and while blocks.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:08:16 -07:00
Bin Gao
b6951b8a63 serial: mrst_max3110: Fix race condition between spi transfers
There is a race between termios configuration and xmit that can cause the
intel_mid_ssp_spi driver to stall.

Serializing spi transactions fixes the problem.

Signed-off-by: Bin Gao <bin.gao@intel.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:08:16 -07:00
Feng Tang
09238443c6 serial: mrst_max3110: Check the irq number before enable/disabe irq in PM hooks
We should check the validity of the irq number before calling
disable_irq() and enable_irq() in the suspend/resume function,
as "max->irq == 0" means the irq is not enabled for max3110
device, otherwise it will hurt device whose irq number is really 0.

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:08:15 -07:00
Shinya Kuribayashi
12082ba2cb serial8250-em: convert to clk_prepare/unprepare
Add calls to clk_prepare and unprepare so that EMMA Mobile EV2 can
migrate to the common clock framework.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
[takashi.yoshii.ze@renesas.com: edited for conflicts]
Signed-off-by: Takashi Yoshii <takashi.yoshii.zj@renesas.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:07:14 -07:00
Ben Hutchings
8eaede49df sysrq: Allow magic SysRq key functions to be disabled through Kconfig
Turn the initial value of sysctl kernel.sysrq (SYSRQ_DEFAULT_ENABLE)
into a Kconfig variable.

Original version by Bastian Blank <waldi@debian.org>.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:01:44 -07:00
Benjamin Herrenschmidt
5c94913c5f tty/hvc_opal: powerpc: Make OPAL HVC device tree accesses endian safe
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-11 16:48:54 +11:00
Benjamin Herrenschmidt
99fc1d91b8 powerpc/hvsi: Fix endian issues in HVSI driver
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-11 16:48:53 +11:00
Rob Herring
5af5073004 drivers: clean-up prom.h implicit includes
Powerpc is a mess of implicit includes by prom.h. Add the necessary
explicit includes to drivers in preparation of prom.h cleanup.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
2013-10-09 20:04:04 -05:00
Greg Kroah-Hartman
b4e788df8d Revert "serial: i.MX: evaluate linux,stdout-path property"
This reverts commit f7d2c0bbdb, as it
causes build errors when the driver is built as a module.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-07 19:06:59 -07:00
Michael Opdenacker
190c6cc328 serial: bfin_uart: remove deprecated IRQF_DISABLED
This patch proposes to remove the use of the IRQF_DISABLED flag

It's a NOOP since 2.6.35 and it will be removed one day.

Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-07 00:13:58 -07:00
Michael Opdenacker
cf81e054d6 serial: tegra: remove deprecated IRQF_DISABLED
This patch proposes to remove the use of the IRQF_DISABLED flag

It's a NOOP since 2.6.35 and it will be removed one day.

Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-07 00:13:58 -07:00
Greg Kroah-Hartman
97a7729a5c Merge 3.12-rc4 into tty-next
We want the tty fixes in this branch as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-06 17:28:16 -07:00
Hector Palacios
9987f76ad2 serial: mxs-auart: set the FIFO size to DMA buffer size
When DMA is enabled (with hardware flow control enabled) the FIFO size
must be set to the size of the DMA buffer, as this is the size the tty
subsystem can use.

Signed-off-by: Hector Palacios <hector.palacios@digi.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-05 18:03:01 -07:00
David Vrabel
a9fbf4d591 xen/hvc: allow xenboot console to be used again
Commit d0380e6c3c (early_printk:
consolidate random copies of identical code) added in 3.10 introduced
a check for con->index == -1 in early_console_register().

Initialize index to -1 for the xenboot console so earlyprintk=xen
works again.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-03 16:12:58 -07:00
Michal Simek
7ea816a0c3 serial: Remove unnecessary amba_set_drvdata()
Driver core clears the driver data to NULL after device_release
or on probe failure, so just remove it from here.

Driver core change:
"device-core: Ensure drvdata = NULL when no driver is bound"
(sha1: 0998d06310)

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-03 16:09:47 -07:00
Tim Kryger
c49436b657 serial: 8250_dw: Improve unwritable LCR workaround
When configured with UART_16550_COMPATIBLE=NO or in versions prior to
the introduction of this option, the Designware UART will ignore writes
to the LCR if the UART is busy.  The current workaround saves a copy of
the last written LCR and re-writes it in the ISR for a special interrupt
that is raised when a write was ignored.

Unfortunately, interrupts are typically disabled prior to performing a
sequence of register writes that include the LCR so the point at which
the retry occurs is too late.  An example is serial8250_do_set_termios()
where an ignored LCR write results in the baud divisor not being set and
instead a garbage character is sent out the transmitter.

Furthermore, since serial_port_out() offers no way to indicate failure,
a serious effort must be made to ensure that the LCR is actually updated
before returning back to the caller.  This is difficult, however, as a
UART that was busy during the first attempt is likely to still be busy
when a subsequent attempt is made unless some extra action is taken.

This updated workaround reads back the LCR after each write to confirm
that the new value was accepted by the hardware.  Should the hardware
ignore a write, the TX/RX FIFOs are cleared and the receive buffer read
before attempting to rewrite the LCR out of the hope that doing so will
force the UART into an idle state.  While this may seem unnecessarily
aggressive, writes to the LCR are used to change the baud rate, parity,
stop bit, or data length so the data that may be lost is likely not
important.  Admittedly, this is far from ideal but it seems to be the
best that can be done given the hardware limitations.

Lastly, the revised workaround doesn't touch the LCR in the ISR, so it
avoids the possibility of a "serial8250: too much work for irq" lock up.
This problem is rare in real situations but can be reproduced easily by
wiring up two UARTs and running the following commands.

  # stty -F /dev/ttyS1 echo
  # stty -F /dev/ttyS2 echo
  # cat /dev/ttyS1 &
  [1] 375
  # echo asdf > /dev/ttyS1
  asdf

  [   27.700000] serial8250: too much work for irq96
  [   27.700000] serial8250: too much work for irq96
  [   27.710000] serial8250: too much work for irq96
  [   27.710000] serial8250: too much work for irq96
  [   27.720000] serial8250: too much work for irq96
  [   27.720000] serial8250: too much work for irq96
  [   27.730000] serial8250: too much work for irq96
  [   27.730000] serial8250: too much work for irq96
  [   27.740000] serial8250: too much work for irq96

Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-03 16:08:03 -07:00
Greg Kroah-Hartman
af8c5b8deb serial: 8250_pci: clean up printk() calls
Move the printk() calls to to dev_*() instead, to tie into the dynamic
debugging infrastructure.

Also change some "raw" printk() calls to dev_err() to provide a better
error message to userspace so it can properly identify the device and
not just have to guess.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-30 19:09:37 -07:00
Bartlomiej Zolnierkiewicz
f829452390 TTY: bfin_jtag_comm: fix incorrect placement of __initdata tag
__initdata tag should be placed between the variable name and equal
sign for the variable to be placed in the intended .init.data section.

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-30 19:09:37 -07:00
Peter Hurley
f8747d4a46 tty: Fix pty master read() after slave closes
Commit f95499c303,
  n_tty: Don't wait for buffer work in read() loop
creates a race window which can cause a pty master read()
to miss the last pty slave write(s) and return -EIO instead,
thus signalling the pty slave is closed. This can happen when
the pty slave is written and immediately closed but before the
tty buffer i/o loop receives the new input; the pty master
read() is scheduled, sees its read buffer is empty and the
pty slave has been closed, and exits.

Because tty_flush_to_ldisc() has significant performance impact
for parallel i/o, rather than revert the commit, special case this
condition (ie., when the read buffer is empty and the 'other' pty
has been closed) and, only then, wait for buffer work to complete
before re-testing if the read buffer is still empty.

As before, subsequent pty master reads return any available data
until no more data is available, and then returns -EIO to
indicate the pty slave has closed.

Reported-by: Mikael Pettersson <mikpelinux@gmail.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-by: Mikael Pettersson <mikpelinux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-30 19:05:56 -07:00