diff options
| author | John Ogness <john.ogness@linutronix.de> | 2022-07-15 09:10:42 +0300 |
|---|---|---|
| committer | Petr Mladek <pmladek@suse.com> | 2022-07-15 11:52:11 +0300 |
| commit | 9023ca0866250d268b047f21e1392e7a81277a54 (patch) | |
| tree | ce45ae54cb0696dc167787b35ba4df28e6017458 /kernel | |
| parent | 07a22b61946f0b80065b0ddcc703b715f84355f5 (diff) | |
| download | linux-9023ca0866250d268b047f21e1392e7a81277a54.tar.xz | |
printk: do not wait for consoles when suspended
The console_stop() and console_start() functions call pr_flush().
When suspending, these functions are called by the serial subsystem
while the serial port is suspended. In this scenario, if there are
any pending messages, a call to pr_flush() will always result in a
timeout because the serial port cannot make forward progress. This
causes longer suspend and resume times.
Add a check in pr_flush() so that it will immediately timeout if
the consoles are suspended.
Fixes: 3b604ca81202 ("printk: add pr_flush()")
Reported-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Tested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220715061042.373640-2-john.ogness@linutronix.de
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/printk/printk.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index b49c6ff6dca0..a1a81fd9889b 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -3380,6 +3380,7 @@ static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progre diff = 0; console_lock(); + for_each_console(c) { if (con && con != c) continue; @@ -3389,11 +3390,19 @@ static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progre if (printk_seq < seq) diff += seq - printk_seq; } - console_unlock(); - if (diff != last_diff && reset_on_progress) + /* + * If consoles are suspended, it cannot be expected that they + * make forward progress, so timeout immediately. @diff is + * still used to return a valid flush status. + */ + if (console_suspended) + remaining = 0; + else if (diff != last_diff && reset_on_progress) remaining = timeout_ms; + console_unlock(); + if (diff == 0 || remaining == 0) break; |