Subject: [merged] drm-fb-helper-dont-sleep-for-screen-unblank-when-an-oopps-is-in-progress.patch removed from -mm tree To: daniel.vetter@xxxxxxxx,airlied@xxxxxxxxx,khlebnikov@xxxxxxxxxx,robdclark@xxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Wed, 22 Jan 2014 12:00:21 -0800 The patch titled Subject: drm/fb-helper: don't sleep for screen unblank when an oops is in progress has been removed from the -mm tree. Its filename was drm-fb-helper-dont-sleep-for-screen-unblank-when-an-oopps-is-in-progress.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Daniel Vetter <daniel.vetter@xxxxxxxx> Subject: drm/fb-helper: don't sleep for screen unblank when an oops is in progress Otherwise the system will burn even brighter and worse, leave the user wondering what's going on exactly. Since we already have a panic handler which will (try) to restore the entire fbdev console mode, we can just bail out. Inspired by a patch from Konstantin Khlebnikov. The callchain leading to this, cut&pasted from Konstantin's original patch: callstack: panic() bust_spinlocks(1) unblank_screen() vc->vc_sw->con_blank() fbcon_blank() fb_blank() info->fbops->fb_blank() drm_fb_helper_blank() drm_fb_helper_dpms() drm_modeset_lock_all() mutex_lock(&dev->mode_config.mutex) Note that the entire locking in the fb helper around panic/sysrq and kdbg is ... non-existant. So we have a decent change of blowing up everything. But since reworking this ties in with funny concepts like the fbdev notifier chain or the impressive things which happen around console_lock while oopsing, I'll leave that as an exercise for braver souls than me. Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx> Cc: Dave Airlie <airlied@xxxxxxxxx> Reviewed-by: Rob Clark <robdclark@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/drm_fb_helper.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff -puN drivers/gpu/drm/drm_fb_helper.c~drm-fb-helper-dont-sleep-for-screen-unblank-when-an-oopps-is-in-progress drivers/gpu/drm/drm_fb_helper.c --- a/drivers/gpu/drm/drm_fb_helper.c~drm-fb-helper-dont-sleep-for-screen-unblank-when-an-oopps-is-in-progress +++ a/drivers/gpu/drm/drm_fb_helper.c @@ -412,6 +412,14 @@ static void drm_fb_helper_dpms(struct fb return; /* + * fbdev->blank can be called from irq context in case of a panic. + * Since we already have our own special panic handler which will + * restore the fbdev console mode completely, just bail out early. + */ + if (oops_in_progress) + return; + + /* * For each CRTC in this fb, turn the connectors on/off. */ drm_modeset_lock_all(dev); _ Patches currently in -mm which might be from daniel.vetter@xxxxxxxx are origin.patch linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html