Matt, please review or suggest an alternative for v4.0-rc. Thanks, Jani. On Thu, 12 Mar 2015, Xi Ruoyao <xry111@xxxxxxxxxxx> wrote: > plane->state->fb and plane->fb should always reference the same FB so > that atomic and legacy codepaths have the same view of display state. > However, there are some places in kernel code that directly set > plane->fb and neglect to update plane->state->fb. If we never do a > successful update through the atomic pipeline, the RmFB cleanup code > will look at the plane->state->fb pointer, which has never actually > been set to a legitimate value, and try to clean it up, leading to > BUG's. > > Add a quick helper function to synchronize plane->state->fb with > plane->fb and call it everywhere the driver tries to manually set > plane->fb outside of the atomic pipeline. In this function, use > drm_atomic_set_fb_for_plane instead of writing plane->state->fb > directly to keep the reference count right. > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88909 > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=93711 > Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx> > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> > Signed-off-by: Xi Ruoyao <xry111@xxxxxxxxxxx> > --- > This is modified from Matt Roper's patch to drm-intel-nightly with > commit id > > afd65eb4cc0578a9c07d621acdb8a570e2782bf7 > > However this bug exists in mainline kernel too, so I created this to > fix it in mainline kernel. > > A minor change is to use drm_atomic_set_fb_for_plane instead of > update reference count manually. > > drivers/gpu/drm/i915/intel_display.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index e730789..c483f2f 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -37,6 +37,7 @@ > #include <drm/i915_drm.h> > #include "i915_drv.h" > #include "i915_trace.h" > +#include <drm/drm_atomic.h> > #include <drm/drm_atomic_helper.h> > #include <drm/drm_dp_helper.h> > #include <drm/drm_crtc_helper.h> > @@ -2416,6 +2417,14 @@ out_unref_obj: > return false; > } > > +/* Update plane->state->fb to match plane->fb after driver-internal updates */ > +static void > +update_state_fb(struct drm_plane *plane) > +{ > + if (plane->fb != plane->state->fb) > + drm_atomic_set_fb_for_plane(plane->state, plane->fb); > +} > + > static void > intel_find_plane_obj(struct intel_crtc *intel_crtc, > struct intel_initial_plane_config *plane_config) > @@ -2462,6 +2471,8 @@ intel_find_plane_obj(struct intel_crtc *intel_crtc, > break; > } > } > + > + update_state_fb(intel_crtc->base.primary); > } > > static void i9xx_update_primary_plane(struct drm_crtc *crtc, > @@ -6650,6 +6661,7 @@ i9xx_get_initial_plane_config(struct intel_crtc *crtc, > plane_config->size); > > crtc->base.primary->fb = fb; > + update_state_fb(crtc->base.primary); > } > > static void chv_crtc_clock_get(struct intel_crtc *crtc, > @@ -7687,6 +7699,7 @@ skylake_get_initial_plane_config(struct intel_crtc *crtc, > plane_config->size); > > crtc->base.primary->fb = fb; > + update_state_fb(crtc->base.primary); > return; > > error: > @@ -7778,6 +7791,7 @@ ironlake_get_initial_plane_config(struct intel_crtc *crtc, > plane_config->size); > > crtc->base.primary->fb = fb; > + update_state_fb(crtc->base.primary); > } > > static bool ironlake_get_pipe_config(struct intel_crtc *crtc, > @@ -9816,6 +9830,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc, > drm_gem_object_reference(&obj->base); > > crtc->primary->fb = fb; > + update_state_fb(crtc->primary); > > work->pending_flip_obj = obj; > > @@ -9884,6 +9899,7 @@ cleanup_unpin: > cleanup_pending: > atomic_dec(&intel_crtc->unpin_work_count); > crtc->primary->fb = old_fb; > + update_state_fb(crtc->primary); > drm_gem_object_unreference(&work->old_fb_obj->base); > drm_gem_object_unreference(&obj->base); > mutex_unlock(&dev->struct_mutex); > @@ -13718,6 +13734,7 @@ void intel_modeset_gem_init(struct drm_device *dev) > to_intel_crtc(c)->pipe); > drm_framebuffer_unreference(c->primary->fb); > c->primary->fb = NULL; > + update_state_fb(c->primary); > } > } > mutex_unlock(&dev->struct_mutex); > -- > 1.9.1 > -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
