5.4-stable review patch. If anyone has any objections, please let me know.
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From: tuhaowen tuhaowen@uniontech.com
[ Upstream commit 4266e8fa56d3d982bf451d382a410b9db432015c ]
When the computer enters sleep status without a monitor connected, the system switches the console to the virtual terminal tty63(SUSPEND_CONSOLE).
If a monitor is subsequently connected before waking up, the system skips the required VT restoration process during wake-up, leaving the console on tty63 instead of switching back to tty1.
To fix this issue, a global flag vt_switch_done is introduced to record whether the system has successfully switched to the suspend console via vt_move_to_console() during suspend.
If the switch was completed, vt_switch_done is set to 1. Later during resume, this flag is checked to ensure that the original console is restored properly by calling vt_move_to_console(orig_fgconsole, 0).
This prevents scenarios where the resume logic skips console restoration due to incorrect detection of the console state, especially when a monitor is reconnected before waking up.
Signed-off-by: tuhaowen tuhaowen@uniontech.com Link: https://patch.msgid.link/20250611032345.29962-1-tuhaowen@uniontech.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/power/console.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/power/console.c b/kernel/power/console.c index fcdf0e14a47d..19c48aa5355d 100644 --- a/kernel/power/console.c +++ b/kernel/power/console.c @@ -16,6 +16,7 @@ #define SUSPEND_CONSOLE (MAX_NR_CONSOLES-1)
static int orig_fgconsole, orig_kmsg; +static bool vt_switch_done;
static DEFINE_MUTEX(vt_switch_mutex);
@@ -136,17 +137,21 @@ void pm_prepare_console(void) if (orig_fgconsole < 0) return;
+ vt_switch_done = true; + orig_kmsg = vt_kmsg_redirect(SUSPEND_CONSOLE); return; }
void pm_restore_console(void) { - if (!pm_vt_switch()) + if (!pm_vt_switch() && !vt_switch_done) return;
if (orig_fgconsole >= 0) { vt_move_to_console(orig_fgconsole, 0); vt_kmsg_redirect(orig_kmsg); } + + vt_switch_done = false; }