linux-stable.git/drivers/tty/serial/sh-sci.c, branch v4.19.296

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

2023-04-20T10:04:39+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

2023-04-20T10:04:39+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

2022-06-14T14:59:32+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

2021-09-22T09:48:07+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()

2021-07-20T14:15:41+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

serial: sh-sci: Fix off-by-one error in FIFO threshold register setting

2021-06-03T06:38:05+00:00

commit 2ea2e019c190ee3973ef7bcaf829d8762e56e635 upstream.

The Receive FIFO Data Count Trigger field (RTRG[6:0]) in the Receive
FIFO Data Count Trigger Register (HSRTRGR) of HSCIF can only hold values
ranging from 0-127.  As the FIFO size is equal to 128 on HSCIF, the user
can write an out-of-range value, touching reserved bits.

Fix this by limiting the trigger value to the FIFO size minus one.
Reverse the order of the checks, to avoid rx_trig becoming zero if the
FIFO size is one.

Note that this change has no impact on other SCIF variants, as their
maximum supported trigger value is lower than the FIFO size anyway, and
the code below takes care of enforcing these limits.

Fixes: a380ed461f66d1b8 ("serial: sh-sci: implement FIFO threshold register setting")
Reported-by: Linh Phung 
Reviewed-by: Wolfram Sang 
Reviewed-by: Ulrich Hecht 
Signed-off-by: Geert Uytterhoeven 
Cc: stable 
Link: https://lore.kernel.org/r/5eff320aef92ffb33d00e57979fd3603bbb4a70f.1620648218.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Make sure status register SCxSR is read in correct sequence

2020-04-29T14:31:34+00:00

commit 3dc4db3662366306e54ddcbda4804acb1258e4ba upstream.

For SCIF and HSCIF interfaces the SCxSR register holds the status of
data that is to be read next from SCxRDR register, But where as for
SCIFA and SCIFB interfaces SCxSR register holds status of data that is
previously read from SCxRDR register.

This patch makes sure the status register is read depending on the port
types so that errors are caught accordingly.

Cc: 
Signed-off-by: Kazuhiro Fujita 
Signed-off-by: Hao Bui 
Signed-off-by: KAZUMI HARADA 
Signed-off-by: Lad Prabhakar 
Tested-by: Geert Uytterhoeven 
Link: https://lore.kernel.org/r/1585333048-31828-1-git-send-email-kazuhiro.fujita.jg@renesas.com
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix crash in rx_timer_fn() on PIO fallback

2019-12-05T08:20:23+00:00

[ Upstream commit 2e948218b7c1262a3830823d6620eb227e3d4e3a ]

When falling back to PIO, active_rx must be set to a different value
than cookie_rx[i], else sci_dma_rx_find_active() will incorrectly find a
match, leading to a NULL pointer dereference in rx_timer_fn() later.

Use zero instead, which is the same value as after driver
initialization.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: sh-sci: Fix TX DMA buffer flushing and workqueue races

2019-07-31T05:27:04+00:00

[ Upstream commit 8493eab02608b0e82f67b892aa72882e510c31d0 ]

When uart_flush_buffer() is called, the .flush_buffer() callback zeroes
the tx_dma_len field.  This may race with the work queue function
handling transmit DMA requests:

  1. If the buffer is flushed before the first DMA API call,
     dmaengine_prep_slave_single() may be called with a zero length,
     causing the DMA request to never complete, leading to messages
     like:

        rcar-dmac e7300000.dma-controller: Channel Address Error happen

     and, with debug enabled:

	sh-sci e6e88000.serial: sci_dma_tx_work_fn: ffff800639b55000: 0...0, cookie 126

     and DMA timeouts.

  2. If the buffer is flushed after the first DMA API call, but before
     the second, dma_sync_single_for_device() may be called with a zero
     length, causing the transmit data not to be flushed to RAM, and
     leading to stale data being output.

Fix this by:
  1. Letting sci_dma_tx_work_fn() return immediately if the transmit
     buffer is empty,
  2. Extending the critical section to cover all DMA preparational work,
     so tx_dma_len stays consistent for all of it,
  3. Using local copies of circ_buf.head and circ_buf.tail, to make sure
     they match the actual operation above.

Reported-by: Eugeniu Rosca 
Suggested-by: Yoshihiro Shimoda 
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Eugeniu Rosca 
Tested-by: Eugeniu Rosca 
Link: https://lore.kernel.org/r/20190624123540.20629-2-geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: sh-sci: Terminate TX DMA during buffer flushing

2019-07-31T05:27:04+00:00

[ Upstream commit 775b7ffd7d6d5db320d99b0a485c51e04dfcf9f1 ]

While the .flush_buffer() callback clears sci_port.tx_dma_len since
commit 1cf4a7efdc71cab8 ("serial: sh-sci: Fix race condition causing
garbage during shutdown"), it does not terminate a transmit DMA
operation that may be in progress.

Fix this by terminating any pending DMA operations, and resetting the
corresponding cookie.

Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Eugeniu Rosca 
Tested-by: Eugeniu Rosca 

Link: https://lore.kernel.org/r/20190624123540.20629-3-geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin