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authorHugh Dickins <hughd@chromium.org>2011-10-17 17:06:40 -0700
committerDave Airlie <airlied@redhat.com>2011-11-10 21:27:34 +0000
commitd68752cf7bb92eafbbe6a0df0d0fab67e87523f6 (patch)
tree19ea6aaef4db1dbb9b12e7271e6da497d9e59ab1 /drivers/gpu/drm
parent1ea6b8f48918282bdca0b32a34095504ee65bab5 (diff)
drm: avoid switching to text console if there is no panic timeout
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 <hughd@google.com> [ Edited commit message and modified to short-circuit panic_timeout < 0 instead of testing panic_timeout >= 0. -Mandeep ] Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Stéphane Marchesin <marcheu@chromium.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu/drm')
-rw-r--r--drivers/gpu/drm/drm_fb_helper.c7
1 files changed, 7 insertions, 0 deletions
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();
}