Hi On Tue, Sep 22, 2015 at 12:33 PM, Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> wrote: > Hey, > > Op 22-09-15 om 11:55 schreef Daniel Vetter: >> From: Matt Roper <matthew.d.roper@xxxxxxxxx> >> >> Starting with commit >> >> commit 28cc504e8d52248962f5b485bdc65f539e3fe21d >> Author: Rob Clark <robdclark@xxxxxxxxx> >> Date: Tue Aug 25 15:36:00 2015 -0400 >> >> drm/i915: enable atomic fb-helper >> >> I've been seeing some panics on i915 when the DRM master shuts down that appear >> to be caused by using an already-freed framebuffer (i.e., we're unexpectedly >> dropping our initial FB's reference count to 0 and freeing it, which causes a >> crash when we try to restore it later). Digging deeper, the state FB >> refcounting is working as expected, but we seem to be missing proper >> refcounting on the legacy plane->fb pointers in the new atomic fbdev code. >> >> Tracking plane->old_fb and then doing a ref/unref at the end of the >> fbdev restore like we do in the legacy ioctl's ensures we don't miscount >> references on plane->fb and avoids the panics. >> >> v2 from Daniel: >> >> Really do what the atomic ioctl does: >> - Also update plane->fb and plane->crtc. >> - Clear out plane->old_fb on failures too. >> >> Cc: Rob Clark <robdclark@xxxxxxxxx> >> Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx >> Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx> (v1) >> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> >> --- >> drivers/gpu/drm/drm_fb_helper.c | 16 ++++++++++++++++ >> 1 file changed, 16 insertions(+) > > Looks sane, but I see a lot of this boilerplate for the plane->fb updates, and we often get it wrong. Like for example in drm_mode_atomic_ioctl. > > Could all the plane->fb and old_fb updates be done by drm_atomic_commit or async_commit instead? If we decide to not care for stale "old_fb" pointers, I agree we should make the commit-helpers do it. Thanks David _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
