From d68752cf7bb92eafbbe6a0df0d0fab67e87523f6 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Mon, 17 Oct 2011 17:06:40 -0700 Subject: [PATCH] drm: avoid switching to text console if there is no panic timeout MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a check for panic_timeout in the drm_fb_helper_panic() notifier: if we're going to reboot immediately, the user will not be able to see the messages anyway, and messing with the video mode may display artifacts, and certainly get into several layers of complexity (including mutexes and memory allocations) which we shall be much safer to avoid. Signed-off-by: Hugh Dickins [ Edited commit message and modified to short-circuit panic_timeout < 0 instead of testing panic_timeout >= 0. -Mandeep ] Signed-off-by: Mandeep Singh Baines Acked-by: David Rientjes Acked-by: Stéphane Marchesin Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_fb_helper.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 80fe39d98b0c..aada26f63dec 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -255,6 +255,13 @@ bool drm_fb_helper_force_kernel_mode(void) int drm_fb_helper_panic(struct notifier_block *n, unsigned long ununsed, void *panic_str) { + /* + * It's a waste of time and effort to switch back to text console + * if the kernel should reboot before panic messages can be seen. + */ + if (panic_timeout < 0) + return 0; + printk(KERN_ERR "panic occurred, switching back to text console\n"); return drm_fb_helper_force_kernel_mode(); } -- GitLab