[ Upstream commit 73b5a5c00be39e23b194bad10e1ea8bb73eee176 ]

It seems a copy&paste mistake that suspend callback removes the GPIO
device. There is no counterpart of this action, means once suspended
there is no more GPIO device available untile full unbind-bind cycle
is performed. Remove suspicious GPIO device removal in suspend.

Fixes: d0aeaa83f0b0 ("serial: exar: split out the exar code from 8250_pci")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240219150627.2101198-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 314c2b399288f0058a8c5b6683292cbde5f1531b ]

The core expects for tx_empty() either TIOCSER_TEMT when the tx is
empty or 0 otherwise. s3c24xx_serial_txempty_nofifo() might return
0x4, and at least uart_get_lsr_info() tries to clear exactly
TIOCSER_TEMT (BIT(1)). Fix tx_empty() to return TIOCSER_TEMT.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Link: https://lore.kernel.org/r/20240119104526.1221243-2-tudor.ambarus@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 8ede8c6f474255b2213cccd7997b993272a8e2f9 ]

Replace g with q.

Helpful when grepping thru source code or logs for
"request" keyword.

Fixes: f65444187a66 ("serial: New serial driver MAX310X")
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20240118152213.2644269-6-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 0e6a92f67c8a94707f7bb27ac29e2bdf3e7c167d ]

The if (c >= 20 && c <= 0x3f) test added in commit 7a99565f8732 is
wrong.  20 is DC4 in ascii and it makes no sense to consider that as the
bottom limit. Instead, it should be 0x20 as in the other test in
the commit above. This is supposed to NOT change anything as we handle
interesting 20-0x20 asciis far before this if.

So for sakeness, change to 0x20 (which is SPACE).

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Fixes: 7a99565f8732 ("vt: ignore csi sequences with intermediate characters.")
Cc: Martin Hostettler <textshell@uchuujin.de>
Link: https://lore.kernel.org/all/ZaP45QY2WEsDqoxg@neutronstar.dyndns.org/
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-4-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 188942f05ce45f80c06f7242ad7478bd204c3387 ]

mips_ejtag_fdc_encode() method expects having a first argument passed of
the "u8 **" type, meanwhile the driver passes the "const char **" type.
That causes the next build-warning:

drivers/tty/mips_ejtag_fdc.c: In function ‘mips_ejtag_fdc_console_write’:
drivers/tty/mips_ejtag_fdc.c:343:32: error: passing argument 1 of ‘mips_ejtag_fdc_encode’ from incompatible pointer type [-Werror=incompatible-pointer-types]
   word = mips_ejtag_fdc_encode(&buf_ptr, &buf_len, 1);
                                ^
drivers/tty/mips_ejtag_fdc.c:216:24: note: expected ‘const u8 ** {aka const unsigned char **}’ but argument is of type ‘const char **’
 static struct fdc_word mips_ejtag_fdc_encode(const u8 **ptrs,
                        ^~~~~~~~~~~~~~~~~~~~~

Fix it by altering the type of the pointer which is passed to the
mips_ejtag_fdc_encode() method.

Fixes: ce7cbd9a6c81 ("tty: mips_ejtag_fdc: use u8 for character pointers")
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

This reverts commit 5c7e105cd156fc9adf5294a83623d7a40c15f9b9.

As identified by KASAN, the simplification done by the cleanup patch
was not legal.

>From tracing through the code, it can be seen that we're transmitting
from a 4096-byte circular buffer. We copy anywhere from 1-4 bytes from
it each time. The simplification runs into trouble when we get near
the end of the circular buffer. For instance, we might start out with
xmit->tail = 4094 and we want to transfer 4 bytes. With the code
before simplification this was no problem. We'd read buf[4094],
buf[4095], buf[0], and buf[1]. With the new code we'll do a
memcpy(&buf[4094], 4) which reads 2 bytes past the end of the buffer
and then skips transmitting what's at buf[0] and buf[1].

KASAN isn't 100% consistent at reporting this for me, but to be extra
confident in the analysis, I added traces of the tail and tx_bytes and
then wrote a test program:

  while true; do
    echo -n "abcdefghijklmnopqrstuvwxyz0" > /dev/ttyMSM0
    sleep .1
  done

I watched the traces over SSH and saw:
  qcom_geni_serial_send_chunk_fifo: 4093 4
  qcom_geni_serial_send_chunk_fifo: 1 3

Which indicated that one byte should be missing. Sure enough the
output that should have been:

  abcdefghijklmnopqrstuvwxyz0

In one case was actually missing a byte:

  abcdefghijklmnopqrstuvwyz0

Running "ls -al" on large directories also made the missing bytes
obvious since columns didn't line up.

While the original code may not be the most elegant, we only talking
about copying up to 4 bytes here. Let's just go back to the code that
worked.

Fixes: 5c7e105cd156 ("tty: serial: simplify qcom_geni_serial_send_chunk_fifo()")
Cc: stable <stable@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240304174952.1.I920a314049b345efd1f69d708e7f74d2213d0b49@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If the remote uart device is not connected or not enabled after booting
up, the CTS line is high by default. At this time, if we enable the flow
control when opening the device(for example, using “stty -F /dev/ttyLP4
crtscts” command), there will be a pending idle preamble(first writing 0
and then writing 1 to UARTCTRL_TE will queue an idle preamble) that
cannot be sent out, resulting in the uart port fail to close(waiting for
TX empty), so the user space stty will have to wait for a long time or
forever.

This is an LPUART IP bug(idle preamble has higher priority than CTS),
here add a workaround patch to enable TX CTS after enabling UARTCTRL_TE,
so that the idle preamble does not get stuck due to CTS is deasserted.

Fixes: 380c966c093e ("tty: serial: fsl_lpuart: add 32-bit register interface support")
Cc: stable <stable@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Link: https://lore.kernel.org/r/20240305015706.1050769-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This is the same issue that was fixed for the VGA text buffer in commit
39cdb68c64d8 ("vt: fix memory overlapping when deleting chars in the
buffer"). The cure is also the same i.e. replace memcpy() with memmove()
due to the overlaping buffers.

Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Fixes: 81732c3b2fed ("tty vt: Fix line garbage in virtual console on command line edition")
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/sn184on2-3p0q-0qrq-0218-895349s4753o@syhkavp.arg
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We accidently met the issue that the bash prompt is not shown after the
previous command done and until the next input if there's only one CPU
(In our issue other CPUs are isolated by isolcpus=). Further analysis
shows it's because the port entering runtime suspend even if there's
still pending chars in the buffer and the pending chars will only be
processed in next device resuming. We are using amba-pl011 and the
problematic flow is like below:

Bash                                         kworker
tty_write()
  file_tty_write()
    n_tty_write()
      uart_write()
        __uart_start()
          pm_runtime_get() // wakeup waker
            queue_work()
                                             pm_runtime_work()
                                               rpm_resume()
                                                status = RPM_RESUMING
                                                serial_port_runtime_resume()
                                                  port->ops->start_tx()
                                                    pl011_tx_chars()
                                                      uart_write_wakeup()
        […]
        __uart_start()
          pm_runtime_get() < 0 // because runtime status = RPM_RESUMING
                               // later data are not commit to the port driver
                                                status = RPM_ACTIVE
                                                rpm_idle() -> rpm_suspend()

This patch tries to fix this by checking the port busy before entering
runtime suspending. A runtime_suspend callback is added for the port
driver. When entering runtime suspend the callback is invoked, if there's
still pending chars in the buffer then flush the buffer.

Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM")
Cc: stable <stable@kernel.org>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20240226152351.40924-1-yangyicong@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When userspace opens the console, we call set_termios() passing a
termios with the console's configured baud rate. Currently this causes
dw8250_set_termios() to disable and then re-enable the UART clock at
the same frequency as it was originally. This can cause corruption
of any concurrent console output. Fix it by skipping the reclocking
if we are already at the correct rate.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Fixes: 4e26b134bd17 ("serial: 8250_dw: clock rate handling for all ACPI platforms")
Cc: stable@vger.kernel.org
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240222192635.1050502-1-pcc@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>