Sven Eckelmann 9e16682c94 tty: serial: msm_serial: Deactivate RX DMA for polling support ... commit 7492ffc90f upstream. The CONSOLE_POLLING mode is used for tools like k(g)db. In this kind of setup, it is often sharing a serial device with the normal system console. This is usually no problem because the polling helpers can consume input values directly (when in kgdb context) and the normal Linux handlers can only consume new input values after kgdb switched back. This is not true anymore when RX DMA is enabled for UARTDM controllers. Single input values can no longer be received correctly. Instead following seems to happen: * on 1. input, some old input is read (continuously) * on 2. input, two old inputs are read (continuously) * on 3. input, three old input values are read (continuously) * on 4. input, 4 previous inputs are received This repeats then for each group of 4 input values. This behavior changes slightly depending on what state the controller was when the first input was received. But this makes working with kgdb basically impossible because control messages are always corrupted when kgdboc tries to parse them. RX DMA should therefore be off when CONSOLE_POLLING is enabled to avoid these kind of problems. No such problem was noticed for TX DMA. Fixes: 9969394501 ("tty: serial: msm: Add RX DMA support") Cc: stable@vger.kernel.org Signed-off-by: Sven Eckelmann <sven@narfation.org> Link: https://lore.kernel.org/r/20211113121050.7266-1-sven@narfation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-12-08 09:01:14 +01:00
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hvc	tty: hvc: replace BUG_ON() with negative return value	2021-12-01 09:23:36 +01:00
ipwireless
serdev
serial	tty: serial: msm_serial: Deactivate RX DMA for polling support	2021-12-08 09:01:14 +01:00
vt	tty: Fix out-of-bound vmalloc access in imageblit	2021-10-06 15:42:29 +02:00
amiserial.c	tty: amiserial: fix TIOCSSERIAL permission check	2021-05-14 09:44:10 +02:00
cyclades.c
ehv_bytechan.c
goldfish.c
isicom.c
Kconfig
Makefile
mips_ejtag_fdc.c
moxa.c	tty: moxa: fix TIOCSSERIAL permission check	2021-05-14 09:44:11 +02:00
moxa.h
mxser.c
mxser.h
n_gsm.c	tty: n_gsm: check error while registering tty devices	2021-05-11 14:04:07 +02:00
n_hdlc.c
n_null.c
n_r3964.c
n_tracerouter.c
n_tracesink.c
n_tracesink.h
n_tty.c
nozomi.c	tty: nozomi: Fix the error handling path of 'nozomi_card_init()'	2021-07-14 16:53:41 +02:00
pty.c
rocket.c
rocket.h
rocket_int.h
synclink.c
synclink_gt.c	tty: synclink_gt: rename a conflicting function name	2021-09-30 10:09:23 +02:00
synclinkmp.c
sysrq.c
tty_audit.c
tty_baudrate.c
tty_buffer.c	tty: tty_buffer: Fix the softlockup issue in flush_to_ldisc	2021-11-26 10:47:16 +01:00
tty_io.c	tty: Fix data race between tiocsti() and flush_to_ldisc()	2021-09-15 09:47:39 +02:00
tty_ioctl.c
tty_jobctrl.c
tty_ldisc.c
tty_ldsem.c
tty_mutex.c
tty_port.c
ttynull.c
vcc.c