linux-stable.git/drivers/tty/serial, branch v5.19.2

tty: serial: qcom-geni-serial: Fix %lu -> %u in print statements

2022-08-17T13:16:01+00:00

[ Upstream commit 0fec518018cc5ceffa706370b6e3acbbb1e3c798 ]

When we multiply an unsigned int by a u32 we still end up with an
unsigned int. That means we should specify "%u" not "%lu" in the
format code.

NOTE: this fix was chosen instead of somehow promoting the value to
"unsigned long" since the max baud rate from the earlier call to
uart_get_baud_rate() is 4000000 and the max sampling rate is 32.
4000000 * 32 = 0x07a12000, not even close to overflowing 32-bits.

Fixes: c474c775716e ("tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate.")
Reported-by: Mark Brown 
Signed-off-by: Douglas Anderson 
Link: https://lore.kernel.org/r/20220802132250.1.Iea061e14157a17e114dbe2eca764568a02d6b889@changeid
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

tty: serial: fsl_lpuart: correct the count of break characters

2022-08-17T13:15:59+00:00

[ Upstream commit 707f816f25590c20e056b3bd4a17ce69b03fe856 ]

The LPUART can't distinguish between a break signal and a framing error,
so need to count the break characters if there is a framing error and
received data is zero instead of the parity error.

Fixes: 5541a9bacfe5 ("serial: fsl_lpuart: handle break and make sysrq work")
Reviewed-by: Michael Walle 
Signed-off-by: Sherry Sun 
Link: https://lore.kernel.org/r/20220725050115.12396-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate.

2022-08-17T13:15:59+00:00

[ Upstream commit c474c775716edd46a51bf8161142bbd1545f8733 ]

In the logic around call to clk_round_rate(), for some corner conditions,
get_clk_div_rate() could return an sub-optimal clock rate. Also, if an
exact clock rate was not found lowest clock was being returned.

Search for suitable clock rate in 2 steps
a) exact match or within 2% tolerance
b) within 5% tolerance
This also takes care of corner conditions.

Fixes: c2194bc999d4 ("tty: serial: qcom-geni-serial: Remove uart frequency table. Instead, find suitable frequency with call to clk_round_rate")
Reviewed-by: Douglas Anderson 
Signed-off-by: Vijaya Krishna Nivarthi 
Link: https://lore.kernel.org/r/1657911343-1909-1-git-send-email-quic_vnivarth@quicinc.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: 8250_bcm2835aux: Add missing clk_disable_unprepare()

2022-08-17T13:15:59+00:00

[ Upstream commit b9f1736e475dba0d6da48fdcb831248ab1597886 ]

The error path when get clock frequency fails in bcm2835aux_serial
driver does not correctly disable the clock.

This flaw was found using a static analysis tool "Hulk Robot", which
reported the following warning when analyzing linux-next/master:

    drivers/tty/serial/8250/8250_bcm2835aux.c:
    warning: clk_disable_unprepare_missing.cocci

The cocci script checks for the existence of clk_disable_unprepare()
paired with clk_prepare_enable().

Add the missing clk_disable_unprepare() to the error path.

Fixes: fcc446c8aa63 ("serial: 8250_bcm2835aux: Add ACPI support")
Reported-by: Hulk Robot 
Reviewed-by: Florian Fainelli 
Signed-off-by: Guo Mengqi 
Link: https://lore.kernel.org/r/20220715023312.37808-1-guomengqi3@huawei.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: 8250_bcm7271: Save/restore RTS in suspend/resume

2022-08-17T13:15:53+00:00

[ Upstream commit 3182efd036c1b955403d131258234896cbd9fbeb ]

Commit 9cabe26e65a8 ("serial: 8250_bcm7271: UART errors after resuming
from S2") prevented an early enabling of RTS during resume, but it did
not actively restore the RTS state after resume.

Fixes: 9cabe26e65a8 ("serial: 8250_bcm7271: UART errors after resuming from S2")
Signed-off-by: Doug Berger 
Signed-off-by: Florian Fainelli 
Link: https://lore.kernel.org/r/20220714031316.404918-1-f.fainelli@gmail.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: 8250_fsl: Don't report FE, PE and OE twice

2022-08-17T13:15:51+00:00

[ Upstream commit 9d3aaceb73acadf134596a2f8db9c451c1332d3d ]

Some Freescale 8250 implementations have the problem that a single long
break results in one irq per character frame time. The code in
fsl8250_handle_irq() that is supposed to handle that uses the BI bit in
lsr_saved_flags to detect such a situation and then skip the second
received character. However it also stores other error bits and so after
a single frame error the character received in the next irq handling is
passed to the upper layer with a frame error, too.

So after a spike on the data line (which is correctly recognized as a
frame error) the following valid character is thrown away, because the
driver reports a frame error for that one, too.

To weaken this problem restrict saving LSR to only the BI bit.

Note however that the handling is still broken:

 - lsr_saved_flags is updated using orig_lsr which is the LSR content
   for the first received char, but there might be more in the FIFO, so
   a character is thrown away that is received later and not necessarily
   the one following the break.
 - The doubled break might be the 2nd and 3rd char in the FIFO, so the
   workaround doesn't catch these, because serial8250_rx_chars() doesn't
   handle the workaround.
 - lsr_saved_flags might have set UART_LSR_BI at the entry of
   fsl8250_handle_irq() which doesn't originate from
   fsl8250_handle_irq()'s "up->lsr_saved_flags |= orig_lsr &
   UART_LSR_BI;" but from e.g. from serial8250_tx_empty().
 - For a long or a short break this isn't about two characters, but more
   or only a single one.

Fixes: 9deaa53ac7fa ("serial: add irq handler for Freescale 16550 errata.")
Acked-by: Ilpo Järvinen 
Signed-off-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20220704085119.55900-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: 8250_dw: Take port lock while accessing LSR

2022-08-17T13:15:48+00:00

[ Upstream commit b9491b2e45d71eb64245560e208897af95ffbf95 ]

Accessing LSR requires port lock because it mutates lsr_saved_flags
in serial_lsr_in().

Fixes: 197eb5c416ff ("serial: 8250_dw: Use serial_lsr_in() in dw8250_handle_irq()")
Reviewed-by: Andy Shevchenko 
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/c5879db7-bee9-93f-526e-872a292442@linux.intel.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: 8250_dw: Store LSR into lsr_saved_flags in dw8250_tx_wait_empty()

2022-08-17T13:15:45+00:00

[ Upstream commit af14f3007e2dca0d112f10f6717ba43093f74e81 ]

Make sure LSR flags are preserved in dw8250_tx_wait_empty(). This
function is called from a low-level out function and therefore cannot
call serial_lsr_in() as it would lead to infinite recursion.

It is borderline if the flags need to be saved here at all since this
code relates to writing LCR register which usually implies no important
characters should be arriving.

Fixes: 914eaf935ec7 ("serial: 8250_dw: Allow TX FIFO to drain before writing to UART_LCR")
Reviewed-by: Andy Shevchenko 
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20220608095431.18376-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: 8250_dw: Use serial_lsr_in() in dw8250_handle_irq()

2022-08-17T13:15:45+00:00

[ Upstream commit 197eb5c416ff0e52d152e6ff59b4e759d2f3e10d ]

dw8250_handle_irq() reads LSR under a few conditions, convert both to
use serial_lsr_in() in order to preserve LSR flags properly across
reads.

Fixes: 424d79183af0 ("serial: 8250_dw: Avoid "too much work" from bogus rx timeout interrupt")
Fixes: aa63d786cea2 ("serial: 8250: dw: Add support for DMA flow controlling devices")
Cc: Douglas Anderson 
Cc: Phil Edworthy 
Cc: Miquel Raynal 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20220608095431.18376-6-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: 8250: Get preserved flags using serial_lsr_in()

2022-08-17T13:15:45+00:00

[ Upstream commit 6a4241e8f9b17aa17f55842d6478f280c22d2b44 ]

serial8250_handle_irq() assumes it's the first to read LSR register.
However, there are 8250 drivers which perform LSR read in their own irq
handler prior to calling serial8250_handle_irq(). As not all flags are
preserved across LSR reads, use serial_lsr_in() helper to get all the
preserved flags.

This commit might fix other commits too besides the ones for DW UART
mentioned below. It's just not clear to me which of the other devices
clear some of the LSR flags on read. AFAIK, nobody has complained about
this problem (either against DW or other devices) so it might not have
that bad impact in the end.

Fixes: 424d79183af0 ("serial: 8250_dw: Avoid "too much work" from bogus rx timeout interrupt")
Fixes: aa63d786cea2 ("serial: 8250: dw: Add support for DMA flow controlling devices")
Reviewed-by: Andy Shevchenko 
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20220608095431.18376-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin