Commit Graph

495403 Commits

Author SHA1 Message Date
Peter Hurley
0ec3f585cf serial: 8250: Refactor LCR computation
Refactor the computation of the LCR register value from termios c_cflag
into a new local function, serial8250_compute_lcr().

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:27 -08:00
Peter Hurley
d1f2f21931 serial: 8250: Move UART_BUG_QUOT workaround
The UART_BUG_QUOT workaround adjusts the divisor computed from the
baud rate by serial8250_get_divisor(). Move the workaround into
serial8250_get_divisor(), so that divisor-from-baud computation
is encapsulated.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:27 -08:00
Johannes Thumshirn
01ba8d6af4 tty: serial: men_z135_uart: Fix driver for changes in hardware
16z135 IP Core has changed so the driver needs to be updated to respect
these changes. The following changes have been made:

* Don't invert the 16z135 modem status register when reading.
* Add module parameter to configure the (baud rate dependent) RX timeout.
  Character timeout in seconds = (timeout_reg * baud_reg * 4)/freq_reg.
* Enable the handling of UART core's automatic flow control feature.
  When AFE is active disable generation of modem status IRQs.
* Rework the handling of IRQs to be conform with newer FPGA versions and
  take precautions not to miss an interrupt because of the destructive read
  of the IIR register.
* Correct men_z135_handle_modem_status(), MSR is stat_reg[15:8] not
  stat_reg[7:0]
* Correct calling of uart_handle_{dcd,cts}_change()
* Reset CLOCAL when CRTSCTS is set

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@men.de>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:27 -08:00
Peter Hurley
b164c9721e serial: core: Simplify console suspend logic in uart_suspend_port()
When the uart port being suspended is a console and consoles are
not suspending (kernel command line contains no_console_suspend),
then no action is performed for that port, and the function can
return early.

If the function has not returned early, then one of the conditions
is not true, so the expression
   (console_suspend_enabled || !uart_console(uport))
must be true and can be eliminated.

Similarly, the expression
   (console_suspend_enabled && uart_console(uport))
simplifies to just uart_console(uport).

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:27 -08:00
Stuart R. Anderson
ea9e9d8029 Specify PCI based UART for earlyprintk
Add support for specifying PCI based UARTs for earlyprintk
using a syntax like "earlyprintk=pciserial,00:18.1,115200",
where 00:18.1 is the BDF of a UART device.

[Slightly tidied from Stuart's original patch]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:27 -08:00
Peter Hurley
d2b6f44779 n_tty: Fix signal handling flushes
BRKINT and ISIG requires input and output flush when a signal char
is received. However, the order of operations is significant since
parallel i/o may be ongoing.

Merge the signal handling for BRKINT with ISIG handling.

Process the signal first. This ensures any ongoing i/o is aborted;
without this, a waiting writer may continue writing after the flush
occurs and after the signal char has been echoed.

Write lock the termios_rwsem, which excludes parallel writers from
pushing new i/o until after the output buffers are flushed; claiming
the write lock is necessary anyway to exclude parallel readers while
the read buffer is flushed.

Subclass the termios_rwsem for ptys since the slave pty performing
the flush may appear to reorder the termios_rwsem->tty buffer lock
lock order; adding annotation clarifies that
  slave tty_buffer lock-> slave termios_rwsem -> master tty_buffer lock
is a valid lock order.

Flush the echo buffer. In this context, the echo buffer is 'output'.
Otherwise, the output will appear discontinuous because the output buffer
was cleared which contains older output than the echo buffer.

Open-code the read buffer flush since the input worker does not need
kicking (this is the input worker).

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:27 -08:00
Peter Hurley
1d1d14da12 pty: Fix buffer flush deadlock
The pty driver does not clear its write buffer when commanded.
This is to avoid an apparent deadlock between parallel flushes from
both pty ends; specifically when handling either BRK or INTR input.
However, parallel flushes from this source is not possible since
the pty master can never be set to BRKINT or ISIG. Parallel flushes
from other sources are possible but these do not threaten deadlocks.

Annotate the tty buffer mutex for lockdep to represent the nested
tty_buffer locking which occurs when the pty slave is processing input
(its buffer mutex held) and receives INTR or BRK and acquires the
linked tty buffer mutex via tty_buffer_flush().

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:27 -08:00
Peter Hurley
3abf87cd3e tty: Make lock subclasses available for other tty locks
Besides nested legacy_mutex locking which is required on pty pair
teardown, other nested pty operations require lock subclassing.

Move lock subclass definition to tty interface header, include/linux/tty.h,
and document its use.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:27 -08:00
Peter Hurley
fb5ef9e7da n_tty: Fix read buffer overwrite when no newline
In canon mode, the read buffer head will advance over the buffer tail
if the input > 4095 bytes without receiving a line termination char.

Discard additional input until a line termination is received.
Before evaluating for overflow, the 'room' value is normalized for
I_PARMRK and 1 byte is reserved for line termination (even in !icanon
mode, in case the mode is switched). The following table shows the
transform:

 actual buffer |  'room' value before overflow calc
  space avail  |    !I_PARMRK    |    I_PARMRK
 --------------------------------------------------
      0        |       -1        |       -1
      1        |        0        |        0
      2        |        1        |        0
      3        |        2        |        0
      4+       |        3        |        1

When !icanon or when icanon and the read buffer contains newlines,
normalized 'room' values of -1 and 0 are clamped to 0, and
'overflow' is 0, so read_head is not adjusted and the input i/o loop
exits (setting no_room if called from flush_to_ldisc()). No input
is discarded since the reader does have input available to read
which ensures forward progress.

When icanon and the read buffer does not contain newlines and the
normalized 'room' value is 0, then overflow and room are reset to 1,
so that the i/o loop will process the next input char normally
(except for parity errors which are ignored). Thus, erasures, signalling
chars, 7-bit mode, etc. will continue to be handled properly.

If the input char processed was not a line termination char, then
the canon_head index will not have advanced, so the normalized 'room'
value will now be -1 and 'overflow' will be set, which indicates the
read_head can safely be reset, effectively erasing the last char
processed.

If the input char processed was a line termination, then the
canon_head index will have advanced, so 'overflow' is cleared to 0,
the read_head is not reset, and 'room' is cleared to 0, which exits
the i/o loop (because the reader now have input available to read
which ensures forward progress).

Note that it is possible for a line termination to be received, and
for the reader to copy the line to the user buffer before the
input i/o loop is ready to process the next input char. This is
why the i/o loop recomputes the room/overflow state with every
input char while handling overflow.

Finally, if the input data was processed without receiving
a line termination (so that overflow is still set), the pty
driver must receive a write wakeup. A pty writer may be waiting
to write more data in n_tty_write() but without unthrottling
here that wakeup will not arrive, and forward progress will halt.
(Normally, the pty writer is woken when the reader reads data out
of the buffer and more space become available).

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Peter Hurley
06c49f9fa3 n_tty: Fix PARMRK over-throttling
If PARMRK is enabled, the available read buffer space computation is
overly-pessimistic, which results in severely throttled i/o, even
in the absence of parity errors. For example, if the 4k read buffer
contains 1k processed data, the input worker will compute available
space of 333 bytes, despite 3k being available. At 1365 chars of
processed data, 0 space available is computed.

*Divide remaining space* by 3, truncating down (if left == 2, left = 0).

Reported-by: Christian Riesch <christian.riesch@omicron.at>

Conflicts:
	drivers/tty/n_tty.c

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Peter Hurley
70aca71f92 n_tty: Fix unordered accesses to lockless read buffer
Add commit_head buffer index, which the producer-side publishes
after input processing in non-canon mode. This ensures the consumer-side
observes correctly-ordered writes in non-canonical mode (ie., the buffer
data is written before the buffer index is advanced). Fix consumer-side
uses of read_cnt() to use commit_head instead.

Add required memory barriers to the tail index to guarantee
the consumer-side has completed the loads before the producer-side
begins writing new data. Open-code the producer-side receive_room()
into the i/o loop.

Remove no-longer-referenced receive_room().

Based on work by Christian Riesch <christian.riesch@omicron.at>

Cc: Christian Riesch <christian.riesch@omicron.at>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Peter Hurley
5e28cca153 n_tty: Simplify throttle threshold calculation
The adjustments performed by receive_room() are to ensure a line
termination can always be written to the read buffer. However,
these adjustments are irrelevant to the throttle threshold (because
the threshold < buffer limit).

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Peter Hurley
a342846f9b n_tty: Fix throttle for canon lines > 3967 chars
The tty driver will be mistakenly throttled if a line termination
has not been received, and the line exceeds 3967 chars. Thus, it is
possible for the driver to stop sending when it has not yet sent
the newline. This does not apply to the pty driver.

Don't throttle until at least one line termination has been
received.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Peter Hurley
2c5dc4641c n_tty: Eliminate receive_room() from consumer/exclusive paths
The input worker never reschedules itself; it only processes input until
either there is no more input or the read buffer is full. So the reader
is responsible for restarting the input worker only if the read buffer
was previously full (no_room == 1) _and_ space is now available to process
more input because the reader has consumed data from the read buffer.

However, computing the actual space available is not required to determine
if the reader has consumed data from the read buffer. This condition is
evaluated in 5 situations, each of which the space avail is already known:
1. n_tty_flush_buffer() - the read buffer is empty; kick the worker
2. n_tty_set_termios() - no data has been consumed; do not kick the worker
       (although it may have kicked the reader so data _will be_ consumed)
3. n_tty_check_unthrottle - avail space > 3968; kick the worker
4. n_tty_read, before leaving - only kick the worker if the reader has
       moved the tail. This prevents unnecessarily kicking the worker
       when timeout-style reading is used.
5. n_tty_read, before sleeping - although it is possible for the read
       buffer to be full and input_available_p() to be false, this can
       only happen when the input worker is racing the reader, in which
       case the reader will have been woken and won't sleep.

Rename n_tty_set_room() to n_tty_kick_worker() to reflect what the
function actually does.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Tomasz Figa
62d38099bf ARM: dts: exynos4: Add stdout-path properties
This patch adds stdout-path property to chosen nodes of Exynos4 boards
to enable use of earlycon feature without the need to hardcode port
number in kernel itself.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Tomasz Figa
b94ba0328d serial: samsung: Add support for early console
This patch adds support for early console initialized from device tree
and kernel command line to all variants of Samsung serial driver.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
[mszyprow: added support for command line based initialization,
           fixed comments, added documentation]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Tested-by: Alim Akhtar <alim.akhtar@samsung.com>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Hisashi Nakamura
8b6ff84c2d serial: sh-sci: Fix R-Car SCIF and HSCIF overrun handling
When fifo overrun happened, the interrupt status refers to
SCLSR register in R-Car SCIF and HSCIF.
Thus, overrun handling takes SCLSR register into account.

Signed-off-by: Hisashi Nakamura <hisashi.nakamura.ak@renesas.com>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Yoshihiro Kaneko
51b31f1c6b serial: sh-sci: Use dev_dbg() to log an error message
Since the driver cannot return from overrun error if characters
are output during overrun process, use dev_dbg() instead of
dev_notice() to log the error message of overrun in syslog.

Based on a patch by Hisashi Nakamura.

Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Andy Shevchenko
9119fba0cf serial: 8250_dma: don't bother DMA with small transfers
If we would like to send amount of data less than FIFO size we better would do
this via PIO mode. Otherwise the overhead could be significant.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Andy Shevchenko
a39d1da11b serial: 8250_core: remove redundant else keyword
Since we return in the first branch the second one doesn't require an
additional else keyword. The patch removes it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Sergei Shtylyov
cb87634172 sh-sci: extend PM methods
In order to make it possible to restore from hibernation not only in Linux but
also in e.g. U-Boot, we have to use sci_{suspend|remove}() for the PM {freeze|
thaw|restore}() methods.  It's handy to achieve this by using SIMPLE_DEV_PM_OPS()
macro, however we have to annotate sci_{suspend|remove}() with '__maybe_unused'
in order to avoid compilation warnings when CONFIG_PM_SLEEP is undefined.

Based on orignal patch by Mikhail Ulyanov <mikhail.ulyanov@cogentembedded.com>.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Peter Hurley
c81622ac42 pty: Fix overlimit memory use
The pty_space() computation is broken; the space already consumed
in the tty buffer is not accounted for.

Use tty_buffer_set_limit(), which enforces the limit automatically.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Nathan Rossi
6ecde472b0 tty: xuartps: Fix RX hang, and TX corruption in termios call
The implementation of flushing the RX FIFO breaks in a number of cases,
it is impossible to ensure an complete flush of the RX FIFO due to the
hardware not allowing the use of the FIFOs when the receiver is disabled
(Reading from the FIFO register does not remove it from the FIFO when
the RX_EN=0 or RX_DIS=1). Additionally during an initial set_termios
call where RX_DIS=1 causes a hang waiting forever for the RX FIFO to
empty. On top of this the FIFO will be cleared by the use of the RXRST
bits on the Control Register, making the RX flush pointless (as it does
not preserve the data read anyway).

Due to the TXRST the TX FIFO and transmitter can be interrupted during
frame trasmission, causing corruption and additionally data lost in the
FIFO. Most other serial drivers do not flush or clear the FIFOs during
a termios configuration change and as such do not have issues with
corruption. For this UART controller is it required that the TXRST/RXRST
bit be flagged during the change, this means that the data in the FIFO
will be dropped when changing configuration. In order to prevent data
loss and corruption of the transmitted data, wait until the TX FIFO is
empty before changing the configuration. The performance of this may
cause the set_termios call to take a longer amount of time especially
on lower baud rates, however it is comparable to the same performance
hit that a console_write call costs.

Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>
Acked-by: Anirudha Sarangi <anirudh@xilinx.com>
Acked-by: Harini Katakam <harinik@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Arnd Bergmann
f3e2d56dce tty/isicom: fix big-endian compile warning
Building an arm allmodconfig kernel triggers a lengthy but harmless
warning in the isicom driver:

drvers/tty/isicom.c: In function 'isicom_send_break':
uapi/linux/swab.h:13:15: warning: integer overflow in expression [-Woverflow]
  (((__u16)(x) & (__u16)0x00ffU) << 8) |   \
               ^
uapi/linux/swab.h:107:2: note: in expansion of macro '___constant_swab16'
  ___constant_swab16(x) :   \
  ^
uapi/linux/byteorder/big_endian.h:34:43: note: in expansion of macro '__swab16'
 #define __cpu_to_le16(x) ((__force __le16)__swab16((x)))
                                           ^
linux/byteorder/generic.h:89:21: note: in expansion of macro '__cpu_to_le16'
 #define cpu_to_le16 __cpu_to_le16
                     ^
include/asm/io.h:270:6: note: in expansion of macro 'cpu_to_le16'
      cpu_to_le16(v),__io(p)); })
      ^
drivers/tty/isicom.c:1058:2: note: in expansion of macro 'outw'
  outw((length & 0xff00), base);
  ^

Apparently, the problem is related to the fact that the value 0xff00,
when used as a 16-bit number, is negative and passed into bitwise
operands of the generic byte swapping code.

Marking the input argument as unsigned in both technically correct
and avoids the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Fabio Estevam
5f9ba5b693 serial: mxs-auart: Remove unneeded zeroing of 'ret'
There is no need to explicitly zero the 'ret' variable as it is properly
initialized in a few lines below as:

ret = serial_mxs_probe_dt(s, pdev);

Remove the unneeded zeroing of 'ret'.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Fabio Estevam
99c932c26d serial: mxs-auart: Check for platform_get_irq() error
We should check whether platform_get_irq() failed, and in the case of error
this needs to be propagated.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Fabio Estevam
6960cd465e serial: mxs-auart: Remove irq from private structure
The irq number is only used inside the probe function, so there is no need
to keep it in the private mxs_auart_port structure.

Use a local 'irq' variable for storing the irq number instead.

Also make its type of 'int' as platform_get_irq() may fail and return a
negative number.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Baruch Siach
c0b18db056 tty/serial: digicolor: remove sysrq reference
The Digicolor USART hardware does not support detecting the BREAK condition.
This means that we can't support sysrq on this hardware. Remove all reference
to sysrq from the code.

This also fixes build when sysrq is disabled:

drivers/tty/serial/digicolor-usart.c: In function 'digicolor_uart_console_write':
drivers/tty/serial/digicolor-usart.c:407:33: error: 'struct uart_port' has no member named 'sysrq'

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Peter Hurley
ee15947cf6 serial: 8250_pnp: Enable PNP_CONSOLE for console ports
When the kernel command line parameter, no_console_suspend, is used,
the console should continue to output console messages during and
after system suspend. For a serial console, the serial core ensures
that the device is not shutdown when no_console_suspend is specified.
However, the default operation of the pnp bus will disable and suspend
the device and no further output occurs.

When registering the 8250 port, if the serial device is a console
set the PNP_CONSOLE capability, which prevents device power-off
if consoles are not suspending.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Peter Hurley
01395d7984 PNP: Allow console to override ACPI device sleep
If the serial console is an ACPI PNP device, the PNP bus always powers
down the device at system suspend, even though the no_console_suspend
command line parameter is specified (eg., when debugging suspend/resume).

Add PNP_CONSOLE capability, which when set, prevents calling both the
->disable() and ->suspend() PNP protocol methods if console suspend
is disabled.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Pramod Gurav
2f7f558c22 tty: serial: msm_serial: Remove console unregistration from driver exit.
unregister_console() will be called from uart_remove_one_port() while
removing the platform driver. So not necessary to call it in driver
exit path.

Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Pramod Gurav
4daba33466 tty: serial: msm_serial: code cleanup in msm_console_setup
The change does following:
 - baud, flow, bits, parity were being overwritten as they were
   being reinitialized after parsing.  Initialize them when they are
   declared so that user provided setting are not overwritten.
 - msm_set_baud_rate() is anyway called in uart_set_options when it calls
   msm_set_termios(). msm_reset() is called when we change the baud rate.
   Hence doing away with both of these calls.
 - CR_CMD_PROTECTION_EN and CR_TX_ENABLE settings are done in msm_set_baud_rate.
   So do away with this here.

Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Heikki Krogerus
0a0d412abe serial: 8250_pci: remove one useless explicit type conversion
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Andy Shevchenko
874e52086f x86, mrst: remove Moorestown specific serial drivers
Intel Moorestown platform support was removed few years ago. This is a follow
up which removes Moorestown specific code for the serial devices. It includes
mrst_max3110 and earlyprintk bits.

This was used on SFI (Medfield, Clovertrail) based platforms as well, though
new ones use normal serial interface for the console service.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: David Cohen <david.a.cohen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:24 -08:00
Fabio Estevam
934084a9d2 serial: imx: Fix imx_flush_buffer()
When running an userspace program that does a 'tcflush(fd, TCIOFLUSH)' call
we still see the last received character in the URXD register afterwards.

Clear UCR2_SRST bit so that the UART FIFO is flushed properly.

Since UCR2_SRST also resets some UART registers, we need to save and restore
some of them.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Fugang Duan <B38611@freescale.com>
Acked-by: Jason Liu <r64343@freecale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:24 -08:00
Stefan Agner
bfc2e07f91 tty: serial: fsl_lpuart: terminate DMA on buffer flush
On uart buffer flush, serial core resets the circular buffer.
If a DMA transfer is in progress at that time, the callback
lpuart_dma_tx_complete will move buffer's tail unconditionally,
hence tail moves beyond head. Use the flush_buffer hook to
terminate the DMA imeaditely and avoid lpuart_dma_tx_complete
being called in this situation.

This bug often showed up while shutdown and lead to duplicate
serial console output.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:09:55 -08:00
Yuan Yao
2fe605df32 serial: fsl-lpuart: disable interrupt when suspend
For power management support, we should disable TX and
TX interrupt so that kernel can prepare for deep sleep.

Retain RX and RX interrupt for wakeup the kernel when
receive the input character.

Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:09:55 -08:00
Stefan Agner
011f5bde62 serial: fsl_lpuart: update RX timer on successful DMA transfer
To end a DMA transfer which did not consume a whole buffer (e.g. one
character only), a RX timer is used. When lots of data are received
the DMA transfer will complete and setup another DMA transfer, which
in turn might complete again. In this cases, it is not necessary to
abort the DMA transfers using the RX timer. This change pushes the
RX timer timeout into the future each time a DMA transfer completed.

Aborting the DMA was not very harmful, since the next received
character lead to setup of another RX DMA.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:09:55 -08:00
Stefan Agner
4a818c4396 serial: fsl_lpuart: move DMA channel request to probe
Move the DMA channel request to probe to avoid requesting the DMA
channel on each opening of the ttyLPx device. This also fixes a
potential issue that TX channel is not freed when only RX channel
allocation fails. The DMA channels are now handled independently,
so one could use UART with DMA only in TX direction for instance.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:09:55 -08:00
Stefan Agner
5f1437f61a serial: fsl_lpuart: avoid new transfer while DMA is running
When the UART is in DMA receive mode (RDMAS set) and one character
just arrived while another interrupt is handled (e.g. TX), the RDRF
(receiver data register full flag) is set due to the water level of
1. But since the DMA will take care of this character, there is no
need to handle it by calling lpuart_prepare_rx. Handling it leads to
adding the RX timeout timer twice:

[   74.336698] Kernel BUG at 80053070 [verbose debug info unavailable]
[   74.342999] Internal error: Oops - BUG: 0 [#1] ARM0:00.00 khungtaskd
[   74.347817] Modules linked in:    0 S  0.0  0.0   0:00.00 writeback
[   74.350926] CPU: 0 PID: 0 Comm: swapper Not tainted 3.19.0-rc3-00001-g39d78e2 #1788
[   74.358617] Hardware name: Freescale Vybrid VF610 (Device Tree)t
[   74.364563] task: 807a7678 ti: 8079c000 task.ti: 8079c000 kblockd
[   74.370002] PC is at add_timer+0x24/0x28.0  0.0   0:00.09 kworker/u2:1
[   74.373960] LR is at lpuart_int+0x15c/0x3d8
[   74.378171] pc : [<80053070>]    lr : [<802e0d88>]    psr: a0010193
[   74.378171] sp : 8079de10  ip : 8079de20  fp : 8079de1c
[   74.389694] r10: 807d44c0  r9 : 8688c300  r8 : 00000013
[   74.394943] r7 : 20010193  r6 : 00000000  r5 : 000000a0  r4 : 86997210
[   74.401498] r3 : ffffa7da  r2 : 80817868  r1 : 86997210  r0 : 86997344
[   74.408052] Flags: NzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
[   74.415489] Control: 10c5387d  Table: 8611c059  DAC: 00000015
[   74.421265] Process swapper (pid: 0, stack limit = 0x8079c230)
...

Solve this by only execute the receiver path (lpuart_prepare_rx) if
the DMA receive mode (RDMAS) is not set. Also, make sure the flag is
cleared on initialization, in case it has been left set.

This can be best reproduced using UART as a serial console, then
running top while dd'ing data into the terminal.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Cc: stable <stable@vger.kernel.org> # 3.14
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:09:55 -08:00
Stefan Agner
4a8588a1cf serial: fsl_lpuart: delete timer on shutdown
If the serial port gets closed while a RX transfer is in progress,
the timer might fire after the serial port shutdown finished. This
leads in a NULL pointer dereference:

[    7.508324] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[    7.516590] pgd = 86348000
[    7.519445] [00000000] *pgd=86179831, *pte=00000000, *ppte=00000000
[    7.526145] Internal error: Oops: 17 [#1] ARM
[    7.530611] Modules linked in:
[    7.533876] CPU: 0 PID: 123 Comm: systemd Not tainted 3.19.0-rc3-00004-g5b11ea7 #1778
[    7.541827] Hardware name: Freescale Vybrid VF610 (Device Tree)
[    7.547862] task: 861c3400 ti: 86ac8000 task.ti: 86ac8000
[    7.553392] PC is at lpuart_timer_func+0x24/0xf8
[    7.558127] LR is at lpuart_timer_func+0x20/0xf8
[    7.562857] pc : [<802df99c>]    lr : [<802df998>]    psr: 600b0113
[    7.562857] sp : 86ac9b90  ip : 86ac9b90  fp : 86ac9bbc
[    7.574467] r10: 80817180  r9 : 80817b98  r8 : 80817998
[    7.579803] r7 : 807acee0  r6 : 86989000  r5 : 00000100  r4 : 86997210
[    7.586444] r3 : 86ac8000  r2 : 86ac9bc0  r1 : 86997210  r0 : 00000000
[    7.593085] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[    7.600341] Control: 10c5387d  Table: 86348059  DAC: 00000015
[    7.606203] Process systemd (pid: 123, stack limit = 0x86ac8230)

Setup the timer on UART startup which allows to delete the timer
unconditionally on shutdown. This also saves the initialization
on each transfer.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Cc: stable <stable@vger.kernel.org> # 3.14
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:09:54 -08:00
Peter Hurley
37480a0568 tty: Prevent untrappable signals from malicious program
Commit 26df6d1340 ("tty: Add EXTPROC support for LINEMODE")
allows a process which has opened a pty master to send _any_ signal
to the process group of the pty slave. Although potentially
exploitable by a malicious program running a setuid program on
a pty slave, it's unknown if this exploit currently exists.

Limit to signals actually used.

Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Howard Chu <hyc@symas.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: <stable@vger.kernel.org> # 2.6.36+
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:09:54 -08:00
Nicolas Pitre
19e3ae6b4f vt: provide notifications on selection changes
The vcs device's poll/fasync support relies on the vt notifier to signal
changes to the screen content.  Notifier invocations were missing for
changes that comes through the selection interface though.  Fix that.

Tested with BRLTTY 5.2.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Cc: Dave Mielke <dave@mielke.cc>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:09:54 -08:00
Dave Airlie
67dc0d4758 vt_buffer: drop console buffer copying optimisations
These two copy to/from VGA memory, however on the Silicon
Motion SMI750 VGA card on a 64-bit system cause console corruption.

This is due to the hw being buggy and not handling a 64-bit transaction
correctly.

We could try and create a 32-bit version of these routines,
but I'm not sure the optimisation is worth much today.

Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1132826

Tested-by: Huawei engineering.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:09:54 -08:00
Greg Kroah-Hartman
61b6b7fbda Merge 3.19-rc5 into tty-next
We want those tty fixes in that release in this branch as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-19 07:02:50 +08:00
Linus Torvalds
ec6f34e5b5 Linux 3.19-rc5 2015-01-18 18:02:20 +12:00
Linus Torvalds
d0ac5d8e67 ARM: SoC fixes
We've been sitting on our fixes branch for a while, so this batch is
 unfortunately on the large side.
 
 A lot of these are tweaks and fixes to device trees, fixing various bugs
 around clocks, reg ranges, etc. There's also a few defconfig updates
 (which are on the late side, no more of those).
 
 All in all the diffstat is bigger than ideal at this time, but the nothing
 in here seems particularly risky.
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Merge tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC fixes from Olof Johansson:
 "We've been sitting on our fixes branch for a while, so this batch is
  unfortunately on the large side.

  A lot of these are tweaks and fixes to device trees, fixing various
  bugs around clocks, reg ranges, etc.  There's also a few defconfig
  updates (which are on the late side, no more of those).

  All in all the diffstat is bigger than ideal at this time, but nothing
  in here seems particularly risky"

* tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (31 commits)
  reset: sunxi: fix spinlock initialization
  ARM: dts: disable CCI on exynos5420 based arndale-octa
  drivers: bus: check cci device tree node status
  ARM: rockchip: disable jtag/sdmmc autoswitching on rk3288
  ARM: nomadik: fix up leftover device tree pins
  ARM: at91: board-dt-sama5: add phy_fixup to override NAND_Tree
  ARM: at91/dt: sam9263: Add missing clocks to lcdc node
  ARM: at91: sama5d3: dt: correct the sound route
  ARM: at91/dt: sama5d4: fix the timer reg length
  ARM: exynos_defconfig: Enable LM90 driver
  ARM: exynos_defconfig: Enable options for display panel support
  arm: dts: Use pmu_system_controller phandle for dp phy
  ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances
  ARM: dts: berlin: correct BG2Q's SM GPIO location.
  ARM: dts: berlin: add broken-cd and set bus width for eMMC in Marvell DMP DT
  ARM: dts: berlin: fix io clk and add missing core clk for BG2Q sdhci2 host
  ARM: dts: Revert disabling of smc91x for n900
  ARM: dts: imx51-babbage: Fix ULPI PHY reset modelling
  ARM: dts: dra7-evm: fix qspi device tree partition size
  ARM: omap2plus_defconfig: use CONFIG_CPUFREQ_DT
  ...
2015-01-18 18:00:40 +12:00
Linus Torvalds
12ba8571ab Small number of fixes for clock drivers and a single null pointer
dereference fix in the framework core code. The driver fixes vary from
 fixing section mismatch warnings to preventing machines from hanging
 (and preventing developers from crying).
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Merge tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux

Pull clock driver fixes from Mike Turquette:
 "Small number of fixes for clock drivers and a single null pointer
  dereference fix in the framework core code.

  The driver fixes vary from fixing section mismatch warnings to
  preventing machines from hanging (and preventing developers from
  crying)"

* tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux:
  clk: fix possible null pointer dereference
  Revert "clk: ppc-corenet: Fix Section mismatch warning"
  clk: rockchip: fix deadlock possibility in cpuclk
  clk: berlin: bg2q: remove non-exist "smemc" gate clock
  clk: at91: keep slow clk enabled to prevent system hang
  clk: rockchip: fix rk3288 cpuclk core dividers
  clk: rockchip: fix rk3066 pll lock bit location
  clk: rockchip: Fix clock gate for rk3188 hclk_emem_peri
  clk: rockchip: add CLK_IGNORE_UNUSED flag to fix rk3066/rk3188 USB Host
2015-01-18 15:29:11 +12:00
Linus Torvalds
901b2082b5 SCSI fixes on 20150117
This is one fix for a Multiqueue sleeping in invalid context problem and a
 MAINTAINER file update for Qlogic.
 
 Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI fixes from James Bottomley:
 "This is one fix for a Multiqueue sleeping in invalid context problem
  and a MAINTAINER file update for Qlogic"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: ->queue_rq can't sleep
  MAINTAINERS: Update maintainer list for qla4xxx
2015-01-18 15:26:52 +12:00
Stanimir Varbanov
c7662fc59c clk: fix possible null pointer dereference
The commit 646cafc6 (clk: Change clk_ops->determine_rate to
return a clk_hw as the best parent) opens a possibility for
null pointer dereference, fix this.

Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-17 11:33:57 -08:00