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authorJohn Ogness <john.ogness@linutronix.de>2022-07-15 08:16:42 +0206
committerPetr Mladek <pmladek@suse.com>2022-07-15 10:52:11 +0200
commit9023ca0866250d268b047f21e1392e7a81277a54 (patch)
treece45ae54cb0696dc167787b35ba4df28e6017458 /kernel/printk
parent07a22b61946f0b80065b0ddcc703b715f84355f5 (diff)
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/printk')
-rw-r--r--kernel/printk/printk.c13
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;