linux-stable.git/drivers/tty/serial/sh-sci.c, branch linux-5.10.y Linux kernel stable tree serial: sh-sci: Increment the runtime usage counter for the earlycon device 2025-06-27T10:04:22+00:00 Claudiu Beznea claudiu.beznea.uj@bp.renesas.com 2025-01-16T18:22:49+00:00 9c839c682fa0eef6f9aa30f4e1616c6fc0b63a87 commit 651dee03696e1dfde6d9a7e8664bbdcd9a10ea7f upstream. In the sh-sci driver, serial ports are mapped to the sci_ports[] array, with earlycon mapped at index zero. The uart_add_one_port() function eventually calls __device_attach(), which, in turn, calls pm_request_idle(). The identified code path is as follows: uart_add_one_port() -> serial_ctrl_register_port() -> serial_core_register_port() -> serial_core_port_device_add() -> serial_base_port_add() -> device_add() -> bus_probe_device() -> device_initial_probe() -> __device_attach() -> // ... if (dev->p->dead) { // ... } else if (dev->driver) { // ... } else { // ... pm_request_idle(dev); // ... } The earlycon device clocks are enabled by the bootloader. However, the pm_request_idle() call in __device_attach() disables the SCI port clocks while earlycon is still active. The earlycon write function, serial_console_write(), calls sci_poll_put_char() via serial_console_putchar(). If the SCI port clocks are disabled, writing to earlycon may sometimes cause the SR.TDFE bit to remain unset indefinitely, causing the while loop in sci_poll_put_char() to never exit. On single-core SoCs, this can result in the system being blocked during boot when this issue occurs. To resolve this, increment the runtime PM usage counter for the earlycon SCI device before registering the UART port. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-6-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 651dee03696e1dfde6d9a7e8664bbdcd9a10ea7f upstream.

In the sh-sci driver, serial ports are mapped to the sci_ports[] array,
with earlycon mapped at index zero.

The uart_add_one_port() function eventually calls __device_attach(),
which, in turn, calls pm_request_idle(). The identified code path is as
follows:

uart_add_one_port() ->
  serial_ctrl_register_port() ->
    serial_core_register_port() ->
      serial_core_port_device_add() ->
        serial_base_port_add() ->
          device_add() ->
            bus_probe_device() ->
              device_initial_probe() ->
                __device_attach() ->
                  // ...
                  if (dev->p->dead) {
                    // ...
                  } else if (dev->driver) {
                    // ...
                  } else {
                    // ...
                    pm_request_idle(dev);
                    // ...
                  }

The earlycon device clocks are enabled by the bootloader. However, the
pm_request_idle() call in __device_attach() disables the SCI port clocks
while earlycon is still active.

The earlycon write function, serial_console_write(), calls
sci_poll_put_char() via serial_console_putchar(). If the SCI port clocks
are disabled, writing to earlycon may sometimes cause the SR.TDFE bit to
remain unset indefinitely, causing the while loop in sci_poll_put_char()
to never exit. On single-core SoCs, this can result in the system being
blocked during boot when this issue occurs.

To resolve this, increment the runtime PM usage counter for the earlycon
SCI device before registering the UART port.

Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support")
Cc: stable@vger.kernel.org
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/20250116182249.3828577-6-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: sh-sci: Clean sci_ports[0] after at earlycon exit 2025-06-27T10:04:08+00:00 Claudiu Beznea claudiu.beznea.uj@bp.renesas.com 2025-06-11T05:00:52+00:00 3f0aef1a4bcb42ec4afe57c2f79f576f4b323413 commit 5f1017069933489add0c08659673443c9905659e upstream. The early_console_setup() function initializes sci_ports[0].port with an object of type struct uart_port obtained from the struct earlycon_device passed as an argument to early_console_setup(). Later, during serial port probing, the serial port used as earlycon (e.g., port A) might be remapped to a different position in the sci_ports[] array, and a different serial port (e.g., port B) might be assigned to slot 0. For example: sci_ports[0] = port B sci_ports[X] = port A In this scenario, the new port mapped at index zero (port B) retains the data associated with the earlycon configuration. Consequently, after the Linux boot process, any access to the serial port now mapped to sci_ports[0] (port B) will block the original earlycon port (port A). To address this, introduce an early_console_exit() function to clean up sci_ports[0] when earlycon is exited. To prevent the cleanup of sci_ports[0] while the serial device is still being used by earlycon, introduce the struct sci_port::probing flag and account for it in early_console_exit(). Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-5-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
commit 5f1017069933489add0c08659673443c9905659e upstream.

The early_console_setup() function initializes sci_ports[0].port with an
object of type struct uart_port obtained from the struct earlycon_device
passed as an argument to early_console_setup().

Later, during serial port probing, the serial port used as earlycon
(e.g., port A) might be remapped to a different position in the sci_ports[]
array, and a different serial port (e.g., port B) might be assigned to slot
0. For example:

sci_ports[0] = port B
sci_ports[X] = port A

In this scenario, the new port mapped at index zero (port B) retains the
data associated with the earlycon configuration. Consequently, after the
Linux boot process, any access to the serial port now mapped to
sci_ports[0] (port B) will block the original earlycon port (port A).

To address this, introduce an early_console_exit() function to clean up
sci_ports[0] when earlycon is exited.

To prevent the cleanup of sci_ports[0] while the serial device is still
being used by earlycon, introduce the struct sci_port::probing flag and
account for it in early_console_exit().

Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support")
Cc: stable@vger.kernel.org
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/20250116182249.3828577-5-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: sh-sci: Move runtime PM enable to sci_probe_single() 2025-06-27T10:04:08+00:00 Claudiu Beznea claudiu.beznea.uj@bp.renesas.com 2025-06-11T05:00:51+00:00 ae1db755ade5f66a4b618350998feb5992315032 commit 239f11209e5f282e16f5241b99256e25dd0614b6 upstream. Relocate the runtime PM enable operation to sci_probe_single(). This change prepares the codebase for upcoming fixes. While at it, replace the existing logic with a direct call to devm_pm_runtime_enable() and remove sci_cleanup_single(). The devm_pm_runtime_enable() function automatically handles disabling runtime PM during driver removal. Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-3-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
commit 239f11209e5f282e16f5241b99256e25dd0614b6 upstream.

Relocate the runtime PM enable operation to sci_probe_single(). This change
prepares the codebase for upcoming fixes.

While at it, replace the existing logic with a direct call to
devm_pm_runtime_enable() and remove sci_cleanup_single(). The
devm_pm_runtime_enable() function automatically handles disabling runtime
PM during driver removal.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/20250116182249.3828577-3-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: sh-sci: Check if TX data was written to device in .tx_empty() 2025-06-27T10:04:08+00:00 Claudiu Beznea claudiu.beznea.uj@bp.renesas.com 2025-06-11T05:00:50+00:00 e78653343f12594c1df537294fcab82fd5440850 commit 7cc0e0a43a91052477c2921f924a37d9c3891f0c upstream. On the Renesas RZ/G3S, when doing suspend to RAM, the uart_suspend_port() is called. The uart_suspend_port() calls 3 times the struct uart_port::ops::tx_empty() before shutting down the port. According to the documentation, the struct uart_port::ops::tx_empty() API tests whether the transmitter FIFO and shifter for the port is empty. The Renesas RZ/G3S SCIFA IP reports the number of data units stored in the transmit FIFO through the FDR (FIFO Data Count Register). The data units in the FIFOs are written in the shift register and transmitted from there. The TEND bit in the Serial Status Register reports if the data was transmitted from the shift register. In the previous code, in the tx_empty() API implemented by the sh-sci driver, it is considered that the TX is empty if the hardware reports the TEND bit set and the number of data units in the FIFO is zero. According to the HW manual, the TEND bit has the following meaning: 0: Transmission is in the waiting state or in progress. 1: Transmission is completed. It has been noticed that when opening the serial device w/o using it and then switch to a power saving mode, the tx_empty() call in the uart_port_suspend() function fails, leading to the "Unable to drain transmitter" message being printed on the console. This is because the TEND=0 if nothing has been transmitted and the FIFOs are empty. As the TEND=0 has double meaning (waiting state, in progress) we can't determined the scenario described above. Add a software workaround for this. This sets a variable if any data has been sent on the serial console (when using PIO) or if the DMA callback has been called (meaning something has been transmitted). In the tx_empty() API the status of the DMA transaction is also checked and if it is completed or in progress the code falls back in checking the hardware registers instead of relying on the software variable. Fixes: 73a19e4c0301 ("serial: sh-sci: Add DMA support.") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20241125115856.513642-1-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [claudiu.beznea: fixed conflict by: - keeping serial_port_out() instead of sci_port_out() in sci_transmit_chars() - keeping !uart_circ_empty(xmit) condition in sci_dma_tx_complete(), after s->tx_occurred = true; assignement] Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
commit 7cc0e0a43a91052477c2921f924a37d9c3891f0c upstream.

On the Renesas RZ/G3S, when doing suspend to RAM, the uart_suspend_port()
is called. The uart_suspend_port() calls 3 times the
struct uart_port::ops::tx_empty() before shutting down the port.

According to the documentation, the struct uart_port::ops::tx_empty()
API tests whether the transmitter FIFO and shifter for the port is
empty.

The Renesas RZ/G3S SCIFA IP reports the number of data units stored in the
transmit FIFO through the FDR (FIFO Data Count Register). The data units
in the FIFOs are written in the shift register and transmitted from there.
The TEND bit in the Serial Status Register reports if the data was
transmitted from the shift register.

In the previous code, in the tx_empty() API implemented by the sh-sci
driver, it is considered that the TX is empty if the hardware reports the
TEND bit set and the number of data units in the FIFO is zero.

According to the HW manual, the TEND bit has the following meaning:

0: Transmission is in the waiting state or in progress.
1: Transmission is completed.

It has been noticed that when opening the serial device w/o using it and
then switch to a power saving mode, the tx_empty() call in the
uart_port_suspend() function fails, leading to the "Unable to drain
transmitter" message being printed on the console. This is because the
TEND=0 if nothing has been transmitted and the FIFOs are empty. As the
TEND=0 has double meaning (waiting state, in progress) we can't
determined the scenario described above.

Add a software workaround for this. This sets a variable if any data has
been sent on the serial console (when using PIO) or if the DMA callback has
been called (meaning something has been transmitted). In the tx_empty()
API the status of the DMA transaction is also checked and if it is
completed or in progress the code falls back in checking the hardware
registers instead of relying on the software variable.

Fixes: 73a19e4c0301 ("serial: sh-sci: Add DMA support.")
Cc: stable@vger.kernel.org
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/20241125115856.513642-1-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[claudiu.beznea: fixed conflict by:
 - keeping serial_port_out() instead of sci_port_out() in
   sci_transmit_chars()
 - keeping !uart_circ_empty(xmit) condition in sci_dma_tx_complete(),
   after s->tx_occurred = true; assignement]
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: sh-sci: Do not probe the serial port if its slot in sci_ports[] is in use 2025-03-13T11:47:09+00:00 Claudiu Beznea claudiu.beznea.uj@bp.renesas.com 2025-01-16T18:22:47+00:00 23a32b7a0627ce258e5131aec1f950d8ef22df49 commit 9f7dea875cc7f9c1a56a5c688290634a59cd1420 upstream. In the sh-sci driver, sci_ports[0] is used by earlycon. If the earlycon is still active when sci_probe() is called and the new serial port is supposed to map to sci_ports[0], return -EBUSY to prevent breaking the earlycon. This situation should occurs in debug scenarios, and users should be aware of the potential conflict. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-4-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9f7dea875cc7f9c1a56a5c688290634a59cd1420 upstream.

In the sh-sci driver, sci_ports[0] is used by earlycon. If the earlycon is
still active when sci_probe() is called and the new serial port is supposed
to map to sci_ports[0], return -EBUSY to prevent breaking the earlycon.

This situation should occurs in debug scenarios, and users should be
aware of the potential conflict.

Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support")
Cc: stable@vger.kernel.org
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/20250116182249.3828577-4-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: sh-sci: Drop __initdata macro for port_cfg 2025-03-13T11:47:09+00:00 Claudiu Beznea claudiu.beznea.uj@bp.renesas.com 2025-01-16T18:22:45+00:00 e176a9c514f6f00fa80a0048a8845b1a3cfd0433 commit eaeee4225dba30bef4d424bdf134a07b7f423e8b upstream. The port_cfg object is used by serial_console_write(), which serves as the write function for the earlycon device. Marking port_cfg as __initdata causes it to be freed after kernel initialization, resulting in earlycon becoming unavailable thereafter. Remove the __initdata macro from port_cfg to resolve this issue. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Fixes: 0b0cced19ab15c9e ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Link: https://lore.kernel.org/r/20250116182249.3828577-2-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit eaeee4225dba30bef4d424bdf134a07b7f423e8b upstream.

The port_cfg object is used by serial_console_write(), which serves as
the write function for the earlycon device. Marking port_cfg as __initdata
causes it to be freed after kernel initialization, resulting in earlycon
becoming unavailable thereafter. Remove the __initdata macro from port_cfg
to resolve this issue.

Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support")
Cc: stable@vger.kernel.org
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Fixes: 0b0cced19ab15c9e ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support")
Link: https://lore.kernel.org/r/20250116182249.3828577-2-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Revert "serial: sh-sci: Clean sci_ports[0] after at earlycon exit" 2024-12-14T18:48:10+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2024-11-30T15:55:56+00:00 fa0e202e23ff1ded146d338ed81cd2bcaac49925 commit 718632467d88e98816fa01ab12681ef1c2aa56f8 upstream. This reverts commit 3791ea69a4858b81e0277f695ca40f5aae40f312. It was reported to cause boot-time issues, so revert it for now. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Fixes: 3791ea69a485 ("serial: sh-sci: Clean sci_ports[0] after at earlycon exit") Cc: stable <stable@kernel.org> Cc: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 718632467d88e98816fa01ab12681ef1c2aa56f8 upstream.

This reverts commit 3791ea69a4858b81e0277f695ca40f5aae40f312.

It was reported to cause boot-time issues, so revert it for now.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 3791ea69a485 ("serial: sh-sci: Clean sci_ports[0] after at earlycon exit")
Cc: stable <stable@kernel.org>
Cc: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: sh-sci: Clean sci_ports[0] after at earlycon exit 2024-12-14T18:48:10+00:00 Claudiu Beznea claudiu.beznea.uj@bp.renesas.com 2024-11-06T12:01:12+00:00 0ff91b3bf53e23fbf7e3b303ebf82567fbd9c9c6 commit 3791ea69a4858b81e0277f695ca40f5aae40f312 upstream. The early_console_setup() function initializes the sci_ports[0].port with an object of type struct uart_port obtained from the object of type struct earlycon_device received as argument by the early_console_setup(). It may happen that later, when the rest of the serial ports are probed, the serial port that was used as earlycon (e.g., port A) to be mapped to a different position in sci_ports[] and the slot 0 to be used by a different serial port (e.g., port B), as follows: sci_ports[0] = port A sci_ports[X] = port B In this case, the new port mapped at index zero will have associated data that was used for earlycon. In case this happens, after Linux boot, any access to the serial port that maps on sci_ports[0] (port A) will block the serial port that was used as earlycon (port B). To fix this, add early_console_exit() that clean the sci_ports[0] at earlycon exit time. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20241106120118.1719888-4-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3791ea69a4858b81e0277f695ca40f5aae40f312 upstream.

The early_console_setup() function initializes the sci_ports[0].port with
an object of type struct uart_port obtained from the object of type
struct earlycon_device received as argument by the early_console_setup().

It may happen that later, when the rest of the serial ports are probed,
the serial port that was used as earlycon (e.g., port A) to be mapped to a
different position in sci_ports[] and the slot 0 to be used by a different
serial port (e.g., port B), as follows:

sci_ports[0] = port A
sci_ports[X] = port B

In this case, the new port mapped at index zero will have associated data
that was used for earlycon.

In case this happens, after Linux boot, any access to the serial port that
maps on sci_ports[0] (port A) will block the serial port that was used as
earlycon (port B).

To fix this, add early_console_exit() that clean the sci_ports[0] at
earlycon exit time.

Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support")
Cc: stable@vger.kernel.org
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/20241106120118.1719888-4-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: sh-sci: protect invalidating RXDMA on shutdown 2024-06-16T11:32:21+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2024-05-06T11:40:17+00:00 158adcb7fd7e6a23cbad50f27685ca2afdb6d15e [ Upstream commit aae20f6e34cd0cbd67a1d0e5877561c40109a81b ] The to-be-fixed commit removed locking when invalidating the DMA RX descriptors on shutdown. It overlooked that there is still a rx_timer running which may still access the protected data. So, re-add the locking. Reported-by: Dirk Behme <dirk.behme@de.bosch.com> Closes: https://lore.kernel.org/r/ee6c9e16-9f29-450e-81da-4a8dceaa8fc7@de.bosch.com Fixes: 2c4ee23530ff ("serial: sh-sci: Postpone DMA release when falling back to PIO") Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Link: https://lore.kernel.org/r/20240506114016.30498-7-wsa+renesas@sang-engineering.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit aae20f6e34cd0cbd67a1d0e5877561c40109a81b ]

The to-be-fixed commit removed locking when invalidating the DMA RX
descriptors on shutdown. It overlooked that there is still a rx_timer
running which may still access the protected data. So, re-add the
locking.

Reported-by: Dirk Behme <dirk.behme@de.bosch.com>
Closes: https://lore.kernel.org/r/ee6c9e16-9f29-450e-81da-4a8dceaa8fc7@de.bosch.com
Fixes: 2c4ee23530ff ("serial: sh-sci: Postpone DMA release when falling back to PIO")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20240506114016.30498-7-wsa+renesas@sang-engineering.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tty: serial: sh-sci: Fix Rx on RZ/G2L SCI 2023-04-20T10:10:23+00:00 Biju Das biju.das.jz@bp.renesas.com 2023-03-21T11:47:50+00:00 25eff5e7f743b68e23da7d33a8a455cf05d5e22c commit f92ed0cd9328aed918ebb0ebb64d259eccbcc6e7 upstream. SCI IP on RZ/G2L alike SoCs do not need regshift compared to other SCI IPs on the SH platform. Currently, it does regshift and configuring Rx wrongly. Drop adding regshift for RZ/G2L alike SoCs. Fixes: dfc80387aefb ("serial: sh-sci: Compute the regshift value for SCI ports") Cc: stable@vger.kernel.org Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> Link: https://lore.kernel.org/r/20230321114753.75038-3-biju.das.jz@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f92ed0cd9328aed918ebb0ebb64d259eccbcc6e7 upstream.

SCI IP on RZ/G2L alike SoCs do not need regshift compared to other SCI
IPs on the SH platform. Currently, it does regshift and configuring Rx
wrongly. Drop adding regshift for RZ/G2L alike SoCs.

Fixes: dfc80387aefb ("serial: sh-sci: Compute the regshift value for SCI ports")
Cc: stable@vger.kernel.org
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230321114753.75038-3-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>