Other serial driver work wants to build on patches now in 4.2-rc4 so
merge the branch so this can properly happen.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 068500e08d.
According to some tests, SDMA support is broken at least for i.MX6 without
HW flow control. Different forms of data-corruption appear either with
the ROM firmware for the SDMA controller as well as when loading Freescale
provided SDMA firmware versions 1.1 or 3.1.
Signed-off-by: David Jander <david@protonic.nl>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the UART has been in use before this driver was loaded, IRQs might be
active and get fired as soon as we set the handler, which will crash
in the spin_lock_irqsave(&sport->port.lock, flags) because port.lock is
not initialized until the port is added at the end of probe.
Signed-off-by: David Jander <david@protonic.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To prevent problems with interrupt latency, and due to the fact, that
the error will be counted anyway (icount.overrun), the dev_err is simply
removed.
Background:
If an rx-fifo overflow occurs a dev_err message was called in interrupt
context. Since dev_err messages are written to console in a synchronous way
(unbuffered), and console may be a serial terminal, this leads to a
highly increased interrupt-latency (several milliseconds).
As a result of the high latency more rx-fifo overflows will happen, and
therefore a feedback loop of errors is created.
Signed-off-by: Manfred Schlaegl <manfred.schlaegl@gmx.at>
Acked-By: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As can be seen in function uart_insert_char (serial_core) the element
buf_overrun of struct uart_icount is used to count overruns of
tty-buffer.
Added support for counting of overruns in imx driver analogue to
serial_core.
Signed-off-by: Manfred Schlaegl <manfred.schlaegl@gmx.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Disable interrupts before requesting them in order to fix a kernel oops
after lauching a kernel via kexec.
Tested on a imx6sl-evk board.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This fixes up a merge issue with the amba-pl011.c driver, and we want
the fixes in this branch as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver configures the IDLE condition to interrupt the SDMA engine.
Since the SDMA UART ROM script doesn't clear the IDLE bit itself, this
caused repeated 1-byte DMA transfers, regardless of available data in the
RX FIFO. Also, when returning due to the IDLE condition, the UART ROM
script already increased its counter, causing residue to be off by one.
This patch clears the IDLE condition to avoid repeated 1-byte DMA transfers
and decreases count by when the DMA transfer was aborted due to the IDLE
condition, fixing serial transfers using DMA on i.MX6Q.
Reported-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The platform_device_id is not modified by the driver and core uses it as
const.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The return value from imx_setup_ufcr() is always 0 and its value is never
checked, so better to remove the return value.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Previously Soft Reset (clear of SRST bit in UCR2 register)
of UART in startup is not protected by lock, which may have race
with console_write, as console_write may occur at anytime even
when UART port is shutdown.
To avoid this race, protect Soft reset of UART port with spin_lock.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 17b8f2a3fd ("serial: imx: add support for half duplex rs485")
introduced the following build warning:
drivers/tty/serial/imx.c: In function 'imx_set_termios':
drivers/tty/serial/imx.c:1301:7: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
Add the suggested braces to avoid the build warning.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The transmitter is expected to be controlled by the UART's RTS pin.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Support for IRDA was added in 2009 in commit v2.6.31-rc1~399^2~2. There
are no in-tree users.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is no benefit in keeping this information in RAM when it's not
used any more, so better use function local variables instead.
These members are unused since c0d1c6b0f0 ("serial: imx: Fix the
reporting of interrupts")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This if (0) exists since the driver was introduced in commit
c49bde83eb6a ([ARM PATCH] 1956/2: Re: Motorola i.MX serial driver)
back in 2004.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The writeable bits in the USR2 register are all "write 1 to
clear" so only write the bits that actually should be cleared.
Fixes: f1f836e420 ("serial: imx: Add Rx Fifo overrun error message")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
UBRC is a read-only register, so we should not store and restore it inside
imx_flush_buffer().
Reported-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
When IGNPAR is set in termios->c_iflag, characters with
framing errors should be ignored.
Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If IGNPAR/INPCK are clear in termios->c_iflag, characters
received with parity or framing errors should be preserved
and passed to the upper layers of the tty stack.
Specifically, the decision of whether to set the character
value to zero should be made by n_tty.c/n_tty_receive_parity_error().
Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds Software flow control support in DMA mode.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After send out x_char in UART driver, x_char needs to be cleared
by UART driver itself, otherwise data in TXFIFO can no longer be
sent out.
Also tx counter needs to be increased to keep track of correct
number of transmitted data.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Other than enable Receiver Overrun Interrupt Enable (UCR4_OREN)
in start_tx interface, UCR4_OREN should be enabled before enable
of Receiver.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Start rx_dma once RXFIFO is not empty that can avoid dma request lost
and causes data delay issue.
Signed-off-by: Robin Gong <b38343@freescale.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
DMA mode for UART can be used even w/o HW flow control with RTS/CTS.
So it need to be initialized and enabled earlier.
Signed-off-by: Anton Bondarenko <anton_bondarenko@mentor.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Terminating the DMA, make sure the interrupt is disabled, too.
This fixes random kernel Oops due to dma_tx_call() called for
invalid transmissions.
If we disable the TDMAEN, make sure it's enabled again if a TX
DMA is started.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently in dma_tx_callback(), no matter if there is still
remaining data pending in circle buffer or not, DMA transmit
will be terminated.
This will result in some data never get transmitted.
In order to fix this issue, call imx_dma_tx() again in
dma_tx_callback, when there is pending data and uart hasn't
been stopped.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 2ad28e3efe.
Instead of always wake up write_wait process in TX callback,
TX callback should call imx_dma_tx() again, and let imx_dma_tx
transfer the remaining data in circle buffer.
The issue with commit 2ad28e3 is, in case there is remaining
data in circle buffer, but no process is waiting on write_wait
queue, then as no following uart_write() will be called after
uart_write_wakeup(), thus cause data loss.
Moreover according to Documentation/serial/driver, uart_write_wakeup()
should be called in case the transmit buffer have dropped below
a threshold.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To synchronize between dma_tx_callback() and imx_dma_tx() use the same
variable, dma_is_txing. This prevents any race between these two functions
and ensures that a new DMA can start only after the first has been
finished.
Before the new DMA can be set up, update the circular buffer logic, first.
Therefore, change dma_is_txing after that update, instead of before.
While doing this, in dma_tx_callback() extend the locking to dma_unmap_sg()
and the update of dma_is_txing.
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
First, reformat the code to exit immediately. This allows us to add
more code in more readable format.
In case the TX DMA was still running, remove and disable it's resources.
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In case dmaengine_prep_slave_sg() fails, add the missing dma_unmap_sg().
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Anton Bondarenko <anton_bondarenko@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Inverting the logic of the if statement for the sg initialization
makes the if statement easier and better to read.
No functional change.
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use imx_start_tx() just to enable the TX interrupt. It's the job of the
TX interrupt ISR to fill the transmit buffer, then. If the transmit buffer
is empty, the TX interrupt should be executed as soon as the start_tx()
enables the interrupt, so there is no reason for the extra
imx_transmit_buffer() call, here. Remove it.
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Andy Lowe <andy_lowe@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Several places are accessing the UCR1 register without locking.
This probably will cause a race issue when another thread
is accessing the same register.
Add locking to preventing concurrent access of the UCR1 register.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add CREAD flag hanlding in set_termios and UART DMA mode
which ignores all received chars when CREAD flag cleared.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Anton Bondarenko <anton_bondarenko@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here's the set of driver core patches for 3.19-rc1.
They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes, just
removing a line in a structure.
Other than that, a few minor driver core and debugfs changes. There are
some ath9k patches coming in through this tree that have been acked by
the wireless maintainers as they relied on the debugfs changes.
Everything has been in linux-next for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core update from Greg KH:
"Here's the set of driver core patches for 3.19-rc1.
They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes,
just removing a line in a structure.
Other than that, a few minor driver core and debugfs changes. There
are some ath9k patches coming in through this tree that have been
acked by the wireless maintainers as they relied on the debugfs
changes.
Everything has been in linux-next for a while"
* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
fs: debugfs: add forward declaration for struct device type
firmware class: Deletion of an unnecessary check before the function call "vunmap"
firmware loader: fix hung task warning dump
devcoredump: provide a one-way disable function
device: Add dev_<level>_once variants
ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
ath: use seq_file api for ath9k debugfs files
debugfs: add helper function to create device related seq_file
drivers/base: cacheinfo: remove noisy error boot message
Revert "core: platform: add warning if driver has no owner"
drivers: base: support cpu cache information interface to userspace via sysfs
drivers: base: add cpu_device_create to support per-cpu devices
topology: replace custom attribute macros with standard DEVICE_ATTR*
cpumask: factor out show_cpumap into separate helper function
driver core: Fix unbalanced device reference in drivers_probe
driver core: fix race with userland in device_add()
sysfs/kernfs: make read requests on pre-alloc files use the buffer.
sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
fs: sysfs: return EGBIG on write if offset is larger than file size
...
When CONFIG_SERIAL_IMX_CONSOLE=n and CONFIG_CONSOLE_POLL=y we get the following
build warning:
drivers/tty/serial/imx.c:306:13: warning: 'imx_port_ucrs_save' defined but not used [-Wunused-function]
drivers/tty/serial/imx.c:315:13: warning: 'imx_port_ucrs_restore' defined but not used [-Wunused-function]
imx_port_ucrs_save/restore are only used under CONFIG_SERIAL_IMX_CONSOLE, so
their definitions should be also be protected only by CONFIG_SERIAL_IMX_CONSOLE.
This was detected when building 'allmodconfig'.
Reported-by: Olof's autobuilder <build@lixom.net>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For the console poll usage, .poll_init() will perform deeper hardware
initialization to ensure the serial port is always active.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Huang Shijie <b32955@freescale.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
imx_put_poll_char() has been simplified to remove the code to disable
interrupts. The present code can corrupt register state when re-entered
from FIQ handler.
Switch to _relaxed() MMIO functions (which are safe for polled I/O and
needed to avoid taking spin locks).
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Huang Shijie <b32955@freescale.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is no real value in displaying "Serial: IMX driver" in every boot.
The uart_register_driver() can fail and even so the "Serial: IMX driver" will
be displayed, which is not really helpful.
This is particularly annoying when booting multi_v7_defconfig kernel on a SoC
that is not a i.MX and even though this message gets displayed.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When kzalloc() fails the core MM will already complain about it, so there is
no need to have the error message locally.
Remove the unneeded error message.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of jumping to 'error_out1' label we can simplify the code and return the
error code directly.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On a imx system with ttymxc0, ttymxc1 and ttymxc4 registered we see the
following output from 'cat /proc/interrupts':
$ cat /proc/interrupts
CPU0
...
58: 39 GIC 58 2020000.serial
67: 115 GIC 67 21f8000.i2c
The only uart irq that appears is ttymxc0, which is the console.
As ttymxc1 and ttymxc4 will only have their irq registered at imx_startup(),
they are not shown right after probe.
Transmitting to ttymxc1 and ttymxc4 will cause their irqs to be registered, but
the output shows:
$ echo "111111" > /dev/ttymxc1
$ echo "444444" > /dev/ttymxc4
$ cat /proc/interrupts
CPU0
...
58: 150 GIC 58 2020000.serial
59: 1 GIC 59
62: 1 GIC 62
67: 115 GIC 67 21f8000.i2c
,which misses printing the associated device address.
In order to fix this, register all the irqs inside the probe function via
devm_request_irq(), which will correctly report the serial interrupts associated
with their correspondent serial device and also helps simplyfing the code by
avoiding the calls to free_irq().
$ echo "111111" > /dev/ttymxc1
$ echo "444444" > /dev/ttymxc4
$ cat /proc/interrupts
CPU0
....
58: 202 GIC 58 2020000.serial
59: 1 GIC 59 21e8000.serial
62: 1 GIC 62 21f4000.serial
67: 115 GIC 67 21f8000.i2c
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The wait_event() makes the application hang for ever in the following case:
[1] the hardware flow control is enabled.
[2] the other end (or the remote end) is terminated, and the TX is still
waiting for the hardware flow control signal to become asserted.
This patch fixes it by changing the wait_event to wait_event_interruptible.
Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the uart port is suspending, the RX data is useless.
So in this case, we can terminate the RX DMA right now.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
when the 'CTSC' bit is negated. 'CTS' has no function when 'CTSC' is asserted.
0: The CTS pin is high (inactive)
1: The CTS pin is low (active)
For throttle, it needs to clear 'CTS' and 'CTSC' bits.
For unthrottle, it needs to enable 'CTS' and 'CTSC' bits.
The patch just fix the issue.
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Looking at the get_poll_char() function of the 8250.c serial driver,
we learn:
* poll_get_char() doesn't have to save/disable/restore the interrupt
registers. No interrupt handling is needed in this function at all.
Remove it.
* Don't block in case there is no data available. So instead blocking
in the do {} while loop, just return with NO_POLL_CHAR, immediately .
Additionally, while the i.MX6 register URXD[7-0] contain the RX_DATA,
the upper bits of this register (URXD[15-10]) might contain some
control flags. To ensure that these are not returned with the data
read, just mask out URXD[7-0].
These changes fix the 'hang' working with kdb:
$ echo ttymxc3 > /sys/module/kgdboc/parameters/kgdboc
$ echo g >/proc/sysrq-trigger
[0]kdb> help
...
<hang>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The serial core expects the UART driver to transmit x_char
(START/STOP chars) even if tx is stopped and before data already
in the tx ring buffer if possible. Also, sending x_char must
not cause additional data in the tx ring buffer to transmit
if tx is stopped.
Cause x_char to be transmitted before any other data is sent.
Auto-stop tx if the tx ring buffer is empty or tx should be stopped.
Only perform one write wakeup if tx ring buffer space is below
threshold.
x_char handling in DMA mode is still broken; add FIXME.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix breakage introduced by
commit c557d392fb,
'serial: Test for no tx data on tx restart'.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 717f3bbab3,
'serial_core: Fix conditional start_tx on ring buffer not empty'
exposes an incorrect assumption in several drivers' start_tx methods;
the tx ring buffer can, in fact, be empty when restarting tx while
performing flow control.
Affected drivers:
sunsab.c
ip22zilog.c
pmac_zilog.c
sunzilog.c
m32r_sio.c
imx.c
Other in-tree serial drivers either are not affected or already
test for empty tx ring buffer before transmitting.
Test for empty tx ring buffer in start_tx() method, after transmitting
x_char (if applicable).
Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Seth Bollinger <sethb@digi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Cc: stable <stable@vger.kernel.org> # 3.15
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit e2f2786606.
Huang reports that this patch is broken and should be reverted.
Cc: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch disables the receiver ready interrupt for imx_stop_rx.
It reduces the interrupt numbers when the uart is going to close
or suspend.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The DMA wait queue makes the code very complicated:
For RX, the @->stop_rx hook does not really stop the RX;
For TX, the @->stop_tx hook does not really stop the TX.
The above make the imx_shutdown has to wait the RX/TX DMA to be finished.
In order to make code more simple, this patch removes the DMA wait queue.
By calling the dmaengine_terminate_all, this patch makes the RX stops
immediately after we call the @->stop_rx hook, so does the TX.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the imx_startup(), we will reset the uart port which will reset all
the FIFOs, including the URXD.
So the code to clear the RX FIFO is redundant. Just remove it.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Current code resets the uart port only when it supports the irda mode.
In actually, we also need to reset the uart port in the non-irda mode.
A hang was caught in the following case:
UART A transmits data to the other end. But the transmission maybe
terminated. In some corner case, the TX FIFO maybe not empty.
The kernel will hang at the imx_set_termios():
............................................................
while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
barrier();
............................................................
This patch resets the uart port all the time in the imx_startup().
And fix the hang.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bit 7 of UCR3 is described in the i.MX reference manuals (with the exception
of i.MX1) as follows:
ADNIMP: Autobaud Detection Not Improved-. Disables new features of
autobaud detection (See Baud Rate Automatic Detection
Protocol, for more details).
0 Autobaud detection new features selected
1 Keep old autobaud detection mechanism
The "new features" mechanism occasionally cause the receiver to get out of sync
and continuously produce received characters of '\xff'.
In order to reproduce the problem:
$ stty -F /dev/ttymxc0 19200
- Change the terminal baudrate to 19200
- Type in the console and it should look good
- Change the terminal baudrate back to 115200
- Type 'b' in the console, then a stream of garbage characters is seen.
Also rename the bit definition as per the reference manual.
Tested on mx6q, mx6dl, mx6solo and mx53.
Based on a patch from Eric Nelson for U-boot.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Eric Nelson <eric.nelson@boundarydevices.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use devm_ioremap_resource() in order to make the code simpler and
it gives proper codes on errors.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current code only wakes up the processes when the circle
buffer has less data then the WAKEUP_CHARS.
But sometimes, the circle buffer may has data more then the WAKEUP_CHARS,
in such case, the processes will hang.
This patch makes it always wakes up the processes in the TX callback.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here's the big tty/serial driver update for 3.13-rc1.
There's some more minor n_tty work here, but nothing like previous
kernel releases. Also some new driver ids, driver updates for new
hardware, and other small things.
All of this has been in linux-next for a while with no issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver updates from Greg KH:
"Here's the big tty/serial driver update for 3.13-rc1.
There's some more minor n_tty work here, but nothing like previous
kernel releases. Also some new driver ids, driver updates for new
hardware, and other small things.
All of this has been in linux-next for a while with no issues"
* tag 'tty-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (84 commits)
serial: omap: fix missing comma
serial: sh-sci: Enable the driver on all ARM platforms
serial: mfd: Staticize local symbols
serial: omap: fix a few checkpatch warnings
serial: omap: improve RS-485 performance
mrst_max3110: fix unbalanced IRQ issue during resume
serial: omap: Add support for optional wake-up
serial: sirf: remove duplicate defines
tty: xuartps: Fix build error when COMMON_CLK is not set
tty: xuartps: Fix build error due to missing forward declaration
tty: xuartps: Fix "may be used uninitialized" build warning
serial: 8250_pci: add Pericom PCIe Serial board Support (12d8:7952/4/8) - Chip PI7C9X7952/4/8
tty: xuartps: Update copyright information
tty: xuartps: Implement suspend/resume callbacks
tty: xuartps: Dynamically adjust to input frequency changes
tty: xuartps: Updating set_baud_rate()
tty: xuartps: Force enable the UART in xuartps_console_write
tty: xuartps: support 64 byte FIFO size
tty: xuartps: Add polled mode support for xuartps
tty: xuartps: Implement BREAK detection, add SYSRQ support
...
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>
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>
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>
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>
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>
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>
This resolves a warning where resource_size_t is larger than void *:
drivers/tty/serial/imx.c:1542:6: warning: cast to pointer from integer
of different size [-Wint-to-pointer-cast]
Since iomem_base is a void *, casting to unsigned long is safe.
It's unclear to me that this comparison is truly needed, but it's there
on several other drivers as well.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit f7d2c0bbd (serial: i.MX: evaluate linux,stdout-path property) introduced
the following sparse warning:
drivers/tty/serial/imx.c:1916:77: warning: Using plain integer as NULL pointer
Pass NULL as the last argument of add_preferred_console() instead of zero.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The slave_config is not initialized, so some of its fields may
be set with random data which may causes the failure in the following
dmaengine_prep_slave_sg().
This patch fixes this issue.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
devicetrees may have the linux,stdout-path property to specify the
console. This patch adds support to the i.MX serial driver for this.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We only enable the DMA support when the following are meet:
[1] The uart port supports the hardware flow control(CTS/RTS).
(Some uart port does not support the CTS/RTS.)
[2] The application enables the CTS/RTS.
[3] The Soc is imx6q.
For the sdma's firmware limit, we do not support the DMA except
the imx6q platform.
[4] The uart is not used as a console.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It was not possible to set custom-baudrates like 62500.
Signed-off-by: Hubert Feurstein <h.feurstein@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We will add the DMA support for the imx uart. For the firmware's limit,
only the imx6 serial chips (including the imx6q, imx6dl, imx6sl) can
support the DMA.
This patch adds the necessary macro and helper to distinguish the
imx6q uart from the other imx uart. Other chips can use the "fsl,imx6q-uart"
to enable the DMA support.
This patch also replaces the check "is_imx21_uart()" with "!is_imx1_uart()".
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The uart_console() check makes the clocks(clk_per and clk_ipg) opened
even when we close the console uart.
This patch enable/disable the clocks in imx_console_write(),
so we can keep the clocks closed when the console uart is closed.
Also remove the clock enable/disable oprations in the probe, we do not
need them any more.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 0998d06310
(device-core: Ensure drvdata = NULL when no driver is bound).
Thus, it is not needed to manually clear the device driver data to NULL.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Barry Song <baohua.song@csr.com>
Acked-by: Tony Prisk <linux@prisktech.co.nz>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit ab78029 (drivers/pinctrl: grab default handles from device core),
we can rely on device core for setting the default pins. Compile tested only.
Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13)
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The console's clocks are disabled after the uart driver is probed.
It makes that we can see less log from the console now
(though we still can get all the log by the `dmesg`).
So enable the clocks for console, and we can see all the log again.
This patch also disables the sport->clk_per when we fail to enable
the sport->clk_ipg;
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When CONFIG_SERIAL_IMX_CONSOLE is not selected the following build warnings
appear:
drivers/tty/serial/imx.c:274:13: warning: 'imx_port_ucrs_save' defined but not used [-Wunused-function]
drivers/tty/serial/imx.c:283:13: warning: 'imx_port_ucrs_restore' defined but not used [-Wunused-function]
imx_port_ucrs_save() and imx_port_ucrs_restore() are only used when
CONFIG_CONSOLE_POLL or CONFIG_SERIAL_IMX_CONSOLE are selected, so protect these
functions declaration with a proper ifdef.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Current code opens the clocks when the uart driver is probed.
This will wastes some power if several uarts are enabled, but not really
used.
So close these clocks for uart, and enable the clocks only when
the uart is used.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The uart works in the DCE mode by default, but sometime we need it
works at the DTE mode.
This patch adds the support for the DTE mode.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We only want to enable hardware flow control if RTS/CTS pins
are connected.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch enables the overrun error (ORE) interrupt and increases the
counter in case of overrun.
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 677fe55 (serial: imx: Fix recursive locking bug) introduces an
uninitialized variable warning as below.
CC drivers/tty/serial/imx.o
drivers/tty/serial/imx.c: In function ‘imx_console_write’:
include/linux/spinlock.h:340:2: warning: ‘flags’ may be used uninitialized in this function [-Wuninitialized]
drivers/tty/serial/imx.c:1214:16: note: ‘flags’ was declared here
Initialize the variable to suppress the warning.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9ec1882df2 (tty: serial: imx: console write routing is unsafe
on SMP) introduced a recursive locking bug in imx_console_write().
The callchain is:
imx_rxint()
spin_lock_irqsave(&sport->port.lock,flags);
...
uart_handle_sysrq_char();
sysrq_function();
printk();
imx_console_write();
spin_lock_irqsave(&sport->port.lock,flags); <--- DEAD
The bad news is that the kernel debugging facilities can dectect the
problem, but the printks never surface on the serial console for
obvious reasons.
There is a similar issue with oops_in_progress. If the kernel crashes
we really don't want to be stuck on the lock and unable to tell what
happened.
In general most UP originated drivers miss these checks and nobody
ever notices because CONFIG_PROVE_LOCKING seems to be still ignored by
a large number of developers.
The solution is to avoid locking in the sysrq case and trylock in the
oops_in_progress case.
This scheme is used in other drivers as well and it would be nice if
we could move this to a common place, so the usual copy/paste/modify
bugs can be avoided.
Now there is another issue with this scheme:
CPU0 CPU1
printk()
rxint()
sysrq_detection() -> sets port->sysrq
return from interrupt
console_write()
if (port->sysrq)
avoid locking
port->sysrq is reset with the next receive character. So as long as
the port->sysrq is not reset and this can take an endless amount of
time if after the break no futher receive character follows, all
console writes happen unlocked.
While the current writer is protected against other console writers by
the console sem, it's unprotected against open/close or other
operations which fiddle with the port. That's what the above mentioned
commit tried to solve.
That's an issue in all drivers which use that scheme and unfortunately
there is no easy workaround. The only solution is to have a separate
indicator port->sysrq_cpu. uart_handle_sysrq_char() then sets it to
smp_processor_id() before calling into handle_sysrq() and resets it to
-1 after that. Then change the locking check to:
if (port->sysrq_cpu == smp_processor_id())
locked = 0;
else if (oops_in_progress)
locked = spin_trylock_irqsave(port->lock, flags);
else
spin_lock_irqsave(port->lock, flags);
That would force all other cpus into the spin_lock path. Problem
solved, but that's way beyond the scope of this fix and really wants
to be implemented in a common function which calls the uart specific
write function to avoid another gazillion of hard to debug
copy/paste/modify bugs.
Reported-and-tested-by: Tim Sander <tim@krieglstein.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable <stable@vger.kernel.org> # 3.6+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit cdc8da3998.
In my attempt to fix a build warning on arm randconfig a build error on
imx_v6_v7_defconfig was introduced, so revert it for now.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If CONFIG_CONSOLE_POLL is not defined, the following build warning happens:
drivers/tty/serial/imx.c:274:13: warning: 'imx_port_ucrs_save' defined but not used [-Wunused-function]
drivers/tty/serial/imx.c:283:13: warning: 'imx_port_ucrs_restore' defined but not used [-Wunused-function]
Move imx_port_ucrs_saver/restore under CONFIG_CONSOLE_POLL ifdef block to fix it.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.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>
