linux-stable.git/drivers/tty/serial/sh-sci.c, branch linux-5.4.y

serial: sh-sci: Do not probe the serial port if its slot in sci_ports[] is in use

2025-03-13T11:43:09+00:00

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 
Link: https://lore.kernel.org/r/20250116182249.3828577-4-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Drop __initdata macro for port_cfg

2025-03-13T11:43:09+00:00

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 
Signed-off-by: Claudiu Beznea 
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 
Signed-off-by: Greg Kroah-Hartman

Revert "serial: sh-sci: Clean sci_ports[0] after at earlycon exit"

2024-12-14T18:44:36+00:00

commit 718632467d88e98816fa01ab12681ef1c2aa56f8 upstream.

This reverts commit 3791ea69a4858b81e0277f695ca40f5aae40f312.

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

Reported-by: Geert Uytterhoeven 
Fixes: 3791ea69a485 ("serial: sh-sci: Clean sci_ports[0] after at earlycon exit")
Cc: stable 
Cc: Claudiu Beznea 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Clean sci_ports[0] after at earlycon exit

2024-12-14T18:44:36+00:00

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 
Link: https://lore.kernel.org/r/20241106120118.1719888-4-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: protect invalidating RXDMA on shutdown

2024-06-16T11:28:43+00:00

[ 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 
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 
Link: https://lore.kernel.org/r/20240506114016.30498-7-wsa+renesas@sang-engineering.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

tty: serial: sh-sci: Fix Rx on RZ/G2L SCI

2023-04-20T10:07:34+00:00

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 
Link: https://lore.kernel.org/r/20230321114753.75038-3-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman

tty: serial: sh-sci: Fix transmit end interrupt handler

2023-04-20T10:07:34+00:00

commit b43a18647f03c87e77d50d6fe74904b61b96323e upstream.

The fourth interrupt on SCI port is transmit end interrupt compared to
the break interrupt on other port types. So, shuffle the interrupts to fix
the transmit end interrupt handler.

Fixes: e1d0be616186 ("sh-sci: Add h8300 SCI")
Cc: stable 
Suggested-by: Geert Uytterhoeven 
Signed-off-by: Biju Das 
Link: https://lore.kernel.org/r/20230317150403.154094-1-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Don't allow CS5-6

2022-06-14T16:11:53+00:00

[ Upstream commit 9b87162de8be26bf3156460b37deee6399fd0fcb ]

Only CS7 and CS8 seem supported but CSIZE is not sanitized from
CS5 or CS6 to CS8.

Set CSIZE correctly so that userspace knows the effective value.
Incorrect CSIZE also results in miscalculation of the frame bits in
tty_get_char_size() or in its predecessor where the roughly the same
code is directly within uart_update_timeout().

Fixes: 1da177e4c3f4 (Linux-2.6.12-rc2)
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20220519081808.3776-6-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: sh-sci: fix break handling for sysrq

2021-09-22T10:26:33+00:00

[ Upstream commit 87b8061bad9bd4b549b2daf36ffbaa57be2789a2 ]

This fixes two issues that cause the sysrq sequence to be inadvertently
aborted on SCIF serial consoles:

- a NUL character remains in the RX queue after a break has been detected,
  which is then passed on to uart_handle_sysrq_char()
- the break interrupt is handled twice on controllers with multiplexed ERI
  and BRI interrupts

Signed-off-by: Ulrich Hecht 
Link: https://lore.kernel.org/r/20210816162201.28801-1-uli+renesas@fpond.eu
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: sh-sci: Stop dmaengine transfer in sci_stop_tx()

2021-07-14T14:53:06+00:00

commit 08a84410a04f05c7c1b8e833f552416d8eb9f6fe upstream.

Stop dmaengine transfer in sci_stop_tx(). Otherwise, the following
message is possible output when system enters suspend and while
transferring data, because clearing TIE bit in SCSCR is not able to
stop any dmaengine transfer.

    sh-sci e6550000.serial: ttySC1: Unable to drain transmitter

Note that this driver has already used some #ifdef in the .c file
so that this patch also uses #ifdef to fix the issue. Otherwise,
build errors happens if the CONFIG_SERIAL_SH_SCI_DMA is disabled.

Fixes: 73a19e4c0301 ("serial: sh-sci: Add DMA support.")
Cc:  # v4.9+
Signed-off-by: Yoshihiro Shimoda 
Link: https://lore.kernel.org/r/20210610110806.277932-1-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman