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* [PATCH] serial: core: fix broken console after suspend
@ 2023-03-01  7:57 Lukasz Majczak
  2023-03-01  8:39 ` Greg Kroah-Hartman
  2023-03-01 11:33 ` Ilpo Järvinen
  0 siblings, 2 replies; 7+ messages in thread
From: Lukasz Majczak @ 2023-03-01  7:57 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Jiri Slaby
  Cc: Guenter Roeck, linux-serial, linux-kernel, upstream,
	Lukasz Majczak, stable

Re-enable the console device after suspending, causes its cflags,
ispeed and ospeed to be set anew, basing on the values stored in
uport->cons. The issue is that these values are set only once,
when parsing console parameters after boot (see uart_set_options()),
next after configuring a port in uart_port_startup() these parameteres
(cflags, ispeed and ospeed) are copied to termios structure and
the orginal one (stored in uport->cons) are cleared, but there is no place
in code where those fields are checked against 0.
When kernel calls uart_resume_port() and setups console, it copies cflags,
ispeed and ospeed values from uart->cons,but those are alread cleared.
The efect is that console is broken.
This patch address this by preserving the cflags, ispeed and
ospeed fields in uart->cons during uart_port_startup().

Signed-off-by: Lukasz Majczak <lma@semihalf.com>
Cc: stable@vger.kernel.org
---
 drivers/tty/serial/serial_core.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 2bd32c8ece39..394a05c09d87 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -225,9 +225,6 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
 			tty->termios.c_cflag = uport->cons->cflag;
 			tty->termios.c_ispeed = uport->cons->ispeed;
 			tty->termios.c_ospeed = uport->cons->ospeed;
-			uport->cons->cflag = 0;
-			uport->cons->ispeed = 0;
-			uport->cons->ospeed = 0;
 		}
 		/*
 		 * Initialise the hardware port settings.
-- 
2.39.2.722.g9855ee24e9-goog


^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2023-03-02 16:43 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-03-01  7:57 [PATCH] serial: core: fix broken console after suspend Lukasz Majczak
2023-03-01  8:39 ` Greg Kroah-Hartman
2023-03-01  9:51   ` Lukasz Majczak
2023-03-01 12:22     ` Greg Kroah-Hartman
2023-03-01 14:09       ` Lukasz Majczak
2023-03-02 16:43         ` Lukasz Majczak
2023-03-01 11:33 ` Ilpo Järvinen

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