On Tue, May 20, 2014 at 11:46:42AM +0300, Ville Syrjälä wrote: > On Tue, May 20, 2014 at 10:03:44AM +0200, Daniel Vetter wrote: > > On Mon, May 19, 2014 at 10:25:19PM +0300, ville.syrjala@xxxxxxxxxxxxxxx wrote: > > > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > > > > On pre-ctg GPU reset also resets the display hardware. Force a mode > > > restore after the GPU reset, and also re-init clock gating. > > > > > > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > --- > > > drivers/gpu/drm/i915/i915_drv.c | 8 ++++++++ > > > 1 file changed, 8 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c > > > index b948c71..2ec3796 100644 > > > --- a/drivers/gpu/drm/i915/i915_drv.c > > > +++ b/drivers/gpu/drm/i915/i915_drv.c > > > @@ -794,6 +794,14 @@ int i915_reset(struct drm_device *dev) > > > if (INTEL_INFO(dev)->gen > 5) > > > intel_reset_gt_powersave(dev); > > > > > > + if (IS_GEN4(dev) && !IS_G4X(dev)) { > > > + intel_init_clock_gating(dev); > > > + > > > + drm_modeset_lock_all(dev); > > > + intel_modeset_setup_hw_state(dev, true); > > > + drm_modeset_unlock_all(dev); > > > > Locking inversion here. I think we need to push this down to the very end. > > We already dropped struct_mutex a bit earlier. Or was there some other > lock you were worried about? Oh right, was just confused by the mutex_unlock in the else branch. > > > Also this leaves the interesting question of what happens with vblank > > waits and friends ... > > Hmm. I guess we might have some kind of refcount problem on our hands w/ > vblanks and whatnot. Might be I'd need to for_each_crtc() .crtc_disable() > before the reset. That would match the g33 spec's recommendation to > disable all planes, but it also does quite a bit more, maybe too much? > But I could try it at least. For full nasties we might need a intel_display_reset which does a few things more and wraps the entire sequence in drm_modeset_lock_all so that nothing can escape. Well except the vblank waiting because drm_irq.c. I think we should grab the crtc->mutex in the vblank ioctl anyway for kms. There's a few more trick bits: - On ilk+ (but might as well do it for g4x+) we don't want to reprobe the interrupt since that breaks a few things like vblanks or pipe crc which we only enable at runtime. If we split this up we could just keep the irq reset for pre-g4x. Still leaves us with racy vblank, but meh. Do we have a vblank-vs-hagn testcase already? - Full deadlock audit for the modeset locks to make sure the gpu reset work can actually execute. - Probably more ... Cheers, Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx