On Tue, Jan 21, 2014 at 11:34 PM, <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > 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> We've merged this twic already in 1b1d5397058f06b and 928c2f0c006bf7f381f58 and then had to take out the superflous hunk again in ecc7e6f3bb8ad56764 For some oddball reason git/patch _really_ gets confused here and loves to readd that hunk a few more times (iirc one of my own trees once even ended up with 3 copies ...). No idea what's going on, but we can drop this on here ;-) Or what exactly was the point of this patch submission, I didn't spot a "dropped from -mm" or similar note, and it doesn't seem to be cc'ed to lists. Cheers, Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
