When building with -Wsometimes-uninitialized, Clang warns:
drivers/tty/serial/qcom_geni_serial.c:1079:6: warning: variable 'baud'
is used uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]
It's not wrong; when options is NULL, baud has no default value. Use
9600 as that is a sane default.
Link: https://github.com/ClangBuiltLinux/linux/issues/395
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The geni set/get_mctrl() functions currently do nothing unless
hardware flow control is enabled. Remove this arbitrary limitation.
Suggested-by: Johan Hovold <johan@kernel.org>
Fixes: 8a8a66a1a1 ("tty: serial: qcom_geni_serial: Add support for flow control")
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use u32 rather than unsigned long for register variables for clarity and
consistency.
Signed-off-by: Ryan Case <ryandcase@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver only supports FIFO mode so setting and checking this variable
is unnecessary. If DMA support is ever added then such checks can be
introduced.
Signed-off-by: Ryan Case <ryandcase@chromium.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The variables of tx_wm and rx_wm were set to the same define value in
all cases, never updated, and the define was sometimes used
interchangably. Remove the variables/function and use the fixed value.
Signed-off-by: Ryan Case <ryandcase@chromium.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A frequent side comment has been to remove the use of writel_relaxed,
readl_relaxed, and mb. This reduces driver complexity and the _relaxed
variants were not known to provide any noticeable performance benefit.
Signed-off-by: Ryan Case <ryandcase@chromium.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a serial console write occured while a UART transmit command was
waiting for a done signal then no further data would be sent until
something new kicked the system into gear. If there is already data
waiting in the circular buffer we must re-enable the tx watermark so we
receive the expected interrupts.
Signed-off-by: Ryan Case <ryandcase@chromium.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Before commit a1fee899e5 ("tty: serial: qcom_geni_serial: Fix
softlock") the size of TX transfers was limited to the TX FIFO size,
and wrap arounds of the UART circular buffer were split into two
transfers. With the commit wrap around are allowed within a transfer.
The TX FIFO of the geni serial port uses a word size of 4 bytes. In
case of a circular buffer wrap within a transfer the driver currently
may write an incomplete word to the FIFO, with some bytes containing
data from the circular buffer and others being zero. Since the
transfer isn't completed yet the zero bytes are sent as if they were
actual data.
Handle wrap arounds of the TX buffer properly and ensure that words
written to the TX FIFO always contain valid data (unless the transfer
is completed).
Fixes: a1fee899e5 ("tty: serial: qcom_geni_serial: Fix softlock")
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Tested-by: Ryan Case <ryandcase@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Disable M_TX_FIFO_WATERMARK_EN after we've sent all data for a given
transaction so we don't continue to receive a flurry of free space
interrupts while waiting for the M_CMD_DONE notification. Re-enable the
watermark when establishing the next transaction.
Also clear the watermark interrupt after filling the FIFO so we do not
receive notification again prior to actually having free space.
Signed-off-by: Ryan Case <ryandcase@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Transfers were being divided into device FIFO sized (64 byte max)
operations which would poll for completion within a spin_lock_irqsave /
spin_unlock_irqrestore block. This both made things slow by waiting for
the FIFO to completely drain before adding further data and would also
result in softlocks on large transmissions.
This patch allows larger transfers with continuous FIFO additions as
space becomes available and removes polling from the interrupt handler.
Signed-off-by: Ryan Case <ryandcase@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Let's take advantage of the new ("serial: core: Allow processing sysrq
at port unlock time") to handle sysrqs more cleanly.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The geni serial driver already had some sysrq code in it, but since
SUPPORT_SYSRQ wasn't defined the code didn't do anything useful.
Let's make it useful by adding that define using the same formula
found in other serial drivers.
In order to prevent deadlock, we'll take a page from the
'msm_serial.c' where the spinlock is released around
uart_handle_sysrq_char(). This seemed better than copying from
'8250_port.c' where we skip locking in the console_write function
since the '8250_port.c' method can cause lockdep warnings when
dropping into kgdb.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We should get 'driver_data' from 'struct device' directly. Going via
platform_device is an unneeded step back and forth.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
UART driver checks for the PM state and denies suspend if state is ACTIVE.
This makes UART to deny suspend when client keeps port open which is not
correct. Instead follow framework and obey suspend-resume callbacks.
Signed-off-by: Mukesh Kumar Savaliya <msavaliy@codeaurora.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If you turn on CONFIG_KGDB then you'll get CONFIG_CONSOLE_POLL
selected.
If you have CONFIG_CONSOLE_POLL selected then the GENI serial driver
was setting RX_BYTES_PW to 1 for _all_ UART ports.
This doesn't seem like such a good idea. Let's only set RX_BYTES_PW
to 1 for the console port.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Mukesh Kumar Savaliya <msavaliy@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the big tty and serial pull request for 4.20-rc1
Lots of little things here, including a merge from the SPI tree in order
to keep things simpler for everyone to sync around for one platform.
Major stuff is:
- tty buffer clearing after use
- atmel_serial fixes and additions
- xilinx uart driver updates
and of course, lots of tiny fixes and additions to individual serial
drivers.
All of these have been in linux-next with no reported issues for a
while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial updates from Greg KH:
"Here is the big tty and serial pull request for 4.20-rc1
Lots of little things here, including a merge from the SPI tree in
order to keep things simpler for everyone to sync around for one
platform.
Major stuff is:
- tty buffer clearing after use
- atmel_serial fixes and additions
- xilinx uart driver updates
and of course, lots of tiny fixes and additions to individual serial
drivers.
All of these have been in linux-next with no reported issues for a
while"
* tag 'tty-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (66 commits)
of: base: Change logic in of_alias_get_alias_list()
of: base: Fix english spelling in of_alias_get_alias_list()
serial: sh-sci: do not warn if DMA transfers are not supported
serial: uartps: Do not allow use aliases >= MAX_UART_INSTANCES
tty: check name length in tty_find_polling_driver()
serial: sh-sci: Add r8a77990 support
tty: wipe buffer if not echoing data
tty: wipe buffer.
serial: fsl_lpuart: Remove the alias node dependence
TTY: sn_console: Replace spin_is_locked() with spin_trylock()
Revert "serial:serial_core: Allow use of CTS for PPS line discipline"
serial: 8250_uniphier: add auto-flow-control support
serial: 8250_uniphier: flatten probe function
serial: 8250_uniphier: remove unused "fifo-size" property
dt-bindings: serial: sh-sci: Document r8a7744 bindings
serial: uartps: Fix missing unlock on error in cdns_get_id()
tty/serial: atmel: add ISO7816 support
tty/serial_core: add ISO7816 infrastructure
serial:serial_core: Allow use of CTS for PPS line discipline
serial: docs: Fix filename for serial reference implementation
...
As done treewide earlier, this catches several more open-coded
allocation size calculations that were added to the kernel during the
merge window. This performs the following mechanical transformations
using Coccinelle:
kvmalloc(a * b, ...) -> kvmalloc_array(a, b, ...)
kvzalloc(a * b, ...) -> kvcalloc(a, b, ...)
devm_kzalloc(..., a * b, ...) -> devm_kcalloc(..., a, b, ...)
Signed-off-by: Kees Cook <keescook@chromium.org>
If you've got the "console" serial port setup to use just as a UART
(AKA there is no "console=ttyMSMX" on the kernel command line) then
certain initialization is skipped. When userspace later tries to do
something with the port then things go boom (specifically, on my
system, some sort of exception hit that caused the system to reboot
itself w/ no error messages).
Let's cleanup / refactor the init so that we always run the same init
code regardless of whether we're using the console.
To make this work, we make rely on qcom_geni_serial_pm doing its job
to turn resources on.
For the record, here is a trace of the order of things (after this
patch) when console= is specified on the command line and we have an
agetty on the port:
qcom_geni_serial_pm: 4 (undefined) => 0 (on)
qcom_geni_console_setup
qcom_geni_serial_port_setup
qcom_geni_serial_console_write
qcom_geni_serial_startup
qcom_geni_serial_start_tx
...and here is the order of things (after this patch) when console= is
_NOT_ specified on the command line and we have an agetty port:
qcom_geni_serial_pm: 4 => 0
qcom_geni_serial_pm: 0 => 3
qcom_geni_serial_pm: 3 => 0
qcom_geni_serial_startup
qcom_geni_serial_port_setup
qcom_geni_serial_pm: 0 => 3
qcom_geni_serial_pm: 3 => 0
qcom_geni_serial_startup
qcom_geni_serial_start_tx
Fixes: c4f528795d ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With gcc 4.1.2:
drivers/tty/serial/qcom_geni_serial.c: In function ‘qcom_geni_serial_probe’:
drivers/tty/serial/qcom_geni_serial.c:1261: warning: ‘drv’ may be used uninitialized in this function
Indeed, if dev.of_node is NULL, drv will be used uninitialized, and
dereferenced in uart_add_one_port(). However, as this driver supports
DT only, dev.of_node will always be valid.
Hence remove the useless check for dev.of_node, killing the warning as a
side effect.
Fixes: 8a8a66a1a1 ("tty: serial: qcom_geni_serial: Add support for flow control")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for flow control functionality in the GENI serial driver
and also support for non-console higher baud rate(upto 4Mbps) usecases.
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>
Signed-off-by: Mohammed Khajapasha <mkhaja@codeaurora.org>
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The GENI serial driver handled transmit by leaving stuff in the
common circular buffer until it had completely caught up to the head,
then clearing it out all at once. This is a suboptimal way to do
transmit, as it leaves data in the circular buffer that could be
freed. Moreover, the logic implementing it is wrong, and it is easy to
get into a situation where the UART infinitely writes out the same buffer.
I could reproduce infinite serial output of the same buffer by running
dmesg, then hitting Ctrl-C. I believe what happened is xmit_size was
something large, marching towards a larger value. Then the generic OS
code flushed out the buffer and replaced it with two characters. Now the
xmit_size is a large value marching towards a small value, which it wasn't
expecting. The driver subtracts xmit_size (very large) from
uart_circ_chars_pending (2), underflows, and repeats ad nauseum. The
locking isn't wrong here, as the locks are held whenever the buffer is
manipulated, it's just that the driver wasn't expecting the buffer to be
flushed out from underneath it in between transmits.
This change reworks transmit to grab what it can from the circular buffer,
and then update ->tail, both fixing the underflow and freeing up space
for a smoother circular experience.
Signed-off-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the driver returns IRQ_HANDLED when spurious interrupts happen.
This is misleading. Fix the behavior by returning IRQ_NONE for spurious
interrupts.
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use iowrite32_rep to write to the hardware FIFO so that the code does
not have to worry about the system endianness.
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While initiating TX, only the register reads need to be ordered. The
register write order either is achieved due to data dependency or is
not required.
Use readl to achieve the read order and remove the unnecessary barrier.
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Perform static initialization of console_port since its initial state has
no run-time dependencies.
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use min3 helper to calculate the minimum value of 3 variables.
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Document reason for newline character counting in console_write
* Document reason for disabling IRQ in the system resume operation
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The platform_get_irq can return error. Assigning the return value to an
unsigned variable and checking it for negative value will always return
false.
Use an intermediate signed variable to get IRQ information, check for any
error and then assign it to 'irq' variable inside uart_port structure.
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We should get drvdata from struct device directly. Going via
platform_device is an unneeded step back and forth.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In case of error, the function platform_get_resource() returns NULL
pointer not ERR_PTR(). The IS_ERR() test in the return value check
should be replaced with NULL test.
Fixes: c4f528795d ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This driver supports GENI based UART Controller in the Qualcomm SOCs. The
Qualcomm Generic Interface (GENI) is a programmable module supporting a
wide range of serial interfaces including UART. This driver support console
operations using FIFO mode of transfer.
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
Signed-off-by: Sagar Dharia <sdharia@codeaurora.org>
Signed-off-by: Doug Anderson <dianders@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
