serial: amba-pl011: fix indefinite RS485 post-send delay

Browse source

The RS485 stop hrtimer is used both to drain the transmitter and to wait
out delay_rts_after_send. The callback cannot tell the two apart, so it
restarts the post-send delay on every expiry and the timer never stops.

Add a WAIT_AFTER_SEND_DELAY state so its expiry ends the stop sequence
instead of restarting the delay.

Fixes: 2c1fd53af2 ("serial: amba-pl011: Fix RTS handling in RS485 mode")
Cc: stable <stable@kernel.org>
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
Link: https://patch.msgid.link/20260731085915.326775-2-fanwu01@zju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Fan Wu 2026-07-31 08:59:13 +00:00 • committed by Greg Kroah-Hartman

parent a7ad003445

commit dcb2f7576c

1 changed files with 6 additions and 2 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

8

drivers/tty/serial/amba-pl011.c

View file