diff mbox

drm/i915: Fix scaling check for 90/270 degree plane rotation

Message ID 1477399503-1710-1-git-send-email-ville.syrjala@linux.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Ville Syrjälä Oct. 25, 2016, 12:45 p.m. UTC 
From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Starting from commit b63a16f6cd89 ("drm/i915: Compute display surface
offset in the plane check hook for SKL+") we've already rotated the src
coordinates by 270 degrees by the time we check if a scaler is needed
or not, so we must not account for the rotation a second time.
Previously we did these steps in the opposite order and hence the
scaler check had to deal with rotation itself. The double rotation
handling causes us to enable a scaler pretty much every time 90/270
degree plane rotation is requested, leading to fuzzier fonts and whatnot.

Cc: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: drm-intel-fixes@lists.freedesktop.org
Reported-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: b63a16f6cd89 ("drm/i915: Compute display surface offset in the plane check hook for SKL+")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

Comments

Tvrtko Ursulin Oct. 27, 2016, 7:46 a.m. UTC | #1 
On 25/10/2016 13:45, ville.syrjala@linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Starting from commit b63a16f6cd89 ("drm/i915: Compute display surface
> offset in the plane check hook for SKL+") we've already rotated the src
> coordinates by 270 degrees by the time we check if a scaler is needed
> or not, so we must not account for the rotation a second time.
> Previously we did these steps in the opposite order and hence the
> scaler check had to deal with rotation itself. The double rotation
> handling causes us to enable a scaler pretty much every time 90/270
> degree plane rotation is requested, leading to fuzzier fonts and whatnot.
>
> Cc: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>
> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Cc: drm-intel-fixes@lists.freedesktop.org
> Reported-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Fixes: b63a16f6cd89 ("drm/i915: Compute display surface offset in the plane check hook for SKL+")
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 5a036999487b..587cd604ce92 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -4671,7 +4671,7 @@ static void cpt_verify_modeset(struct drm_device *dev, int pipe)
>
>  static int
>  skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
> -		  unsigned scaler_user, int *scaler_id, unsigned int rotation,
> +		  unsigned scaler_user, int *scaler_id,
>  		  int src_w, int src_h, int dst_w, int dst_h)
>  {
>  	struct intel_crtc_scaler_state *scaler_state =
> @@ -4680,9 +4680,12 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
>  		to_intel_crtc(crtc_state->base.crtc);
>  	int need_scaling;
>
> -	need_scaling = drm_rotation_90_or_270(rotation) ?
> -		(src_h != dst_w || src_w != dst_h):
> -		(src_w != dst_w || src_h != dst_h);
> +	/*
> +	 * Src coordinates are already rotated by 270 degrees for
> +	 * the 90/270 degree plane rotation cases (to match the
> +	 * GTT mapping), hence no need to account for rotation here.
> +	 */
> +	need_scaling = src_w != dst_w || src_h != dst_h;
>
>  	/*
>  	 * if plane is being disabled or scaler is no more required or force detach
> @@ -4749,7 +4752,7 @@ int skl_update_scaler_crtc(struct intel_crtc_state *state)
>  		      intel_crtc->pipe, SKL_CRTC_INDEX);
>
>  	return skl_update_scaler(state, !state->base.active, SKL_CRTC_INDEX,
> -		&state->scaler_state.scaler_id, DRM_ROTATE_0,
> +		&state->scaler_state.scaler_id,
>  		state->pipe_src_w, state->pipe_src_h,
>  		adjusted_mode->crtc_hdisplay, adjusted_mode->crtc_vdisplay);
>  }
> @@ -4783,7 +4786,6 @@ static int skl_update_scaler_plane(struct intel_crtc_state *crtc_state,
>  	ret = skl_update_scaler(crtc_state, force_detach,
>  				drm_plane_index(&intel_plane->base),
>  				&plane_state->scaler_id,
> -				plane_state->base.rotation,
>  				drm_rect_width(&plane_state->base.src) >> 16,
>  				drm_rect_height(&plane_state->base.src) >> 16,
>  				drm_rect_width(&plane_state->base.dst),
>

Tested-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

After this only the DRM core revert remains. Is that one something of a 
workaround or actually could get in?

Regards,

Tvrtko
Chris Wilson Oct. 27, 2016, 7:55 a.m. UTC | #2 
On Thu, Oct 27, 2016 at 08:46:50AM +0100, Tvrtko Ursulin wrote:
> 
> On 25/10/2016 13:45, ville.syrjala@linux.intel.com wrote:
> >From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >
> >Starting from commit b63a16f6cd89 ("drm/i915: Compute display surface
> >offset in the plane check hook for SKL+") we've already rotated the src
> >coordinates by 270 degrees by the time we check if a scaler is needed
> >or not, so we must not account for the rotation a second time.
> >Previously we did these steps in the opposite order and hence the
> >scaler check had to deal with rotation itself. The double rotation
> >handling causes us to enable a scaler pretty much every time 90/270
> >degree plane rotation is requested, leading to fuzzier fonts and whatnot.
> >
> >Cc: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>
> >Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> >Cc: drm-intel-fixes@lists.freedesktop.org
> >Reported-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> >Fixes: b63a16f6cd89 ("drm/i915: Compute display surface offset in the plane check hook for SKL+")
> >Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >---
> > drivers/gpu/drm/i915/intel_display.c | 14 ++++++++------
> > 1 file changed, 8 insertions(+), 6 deletions(-)
> >
> >diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> >index 5a036999487b..587cd604ce92 100644
> >--- a/drivers/gpu/drm/i915/intel_display.c
> >+++ b/drivers/gpu/drm/i915/intel_display.c
> >@@ -4671,7 +4671,7 @@ static void cpt_verify_modeset(struct drm_device *dev, int pipe)
> >
> > static int
> > skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
> >-		  unsigned scaler_user, int *scaler_id, unsigned int rotation,
> >+		  unsigned scaler_user, int *scaler_id,
> > 		  int src_w, int src_h, int dst_w, int dst_h)
> > {
> > 	struct intel_crtc_scaler_state *scaler_state =
> >@@ -4680,9 +4680,12 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
> > 		to_intel_crtc(crtc_state->base.crtc);
> > 	int need_scaling;
> >
> >-	need_scaling = drm_rotation_90_or_270(rotation) ?
> >-		(src_h != dst_w || src_w != dst_h):
> >-		(src_w != dst_w || src_h != dst_h);
> >+	/*
> >+	 * Src coordinates are already rotated by 270 degrees for
> >+	 * the 90/270 degree plane rotation cases (to match the
> >+	 * GTT mapping), hence no need to account for rotation here.
> >+	 */
> >+	need_scaling = src_w != dst_w || src_h != dst_h;
> >
> > 	/*
> > 	 * if plane is being disabled or scaler is no more required or force detach
> >@@ -4749,7 +4752,7 @@ int skl_update_scaler_crtc(struct intel_crtc_state *state)
> > 		      intel_crtc->pipe, SKL_CRTC_INDEX);
> >
> > 	return skl_update_scaler(state, !state->base.active, SKL_CRTC_INDEX,
> >-		&state->scaler_state.scaler_id, DRM_ROTATE_0,
> >+		&state->scaler_state.scaler_id,
> > 		state->pipe_src_w, state->pipe_src_h,
> > 		adjusted_mode->crtc_hdisplay, adjusted_mode->crtc_vdisplay);
> > }
> >@@ -4783,7 +4786,6 @@ static int skl_update_scaler_plane(struct intel_crtc_state *crtc_state,
> > 	ret = skl_update_scaler(crtc_state, force_detach,
> > 				drm_plane_index(&intel_plane->base),
> > 				&plane_state->scaler_id,
> >-				plane_state->base.rotation,
> > 				drm_rect_width(&plane_state->base.src) >> 16,
> > 				drm_rect_height(&plane_state->base.src) >> 16,
> > 				drm_rect_width(&plane_state->base.dst),
> >
> 
> Tested-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> 
> After this only the DRM core revert remains. Is that one something
> of a workaround or actually could get in?

It itself is a workaround. There are more reasons why it is broken for
us than just getting rotation wrong (it breaks the render-vs-modeset
ordering, which is both ABI and required for us to prevent GPU hangs).
-Chris
Daniel Vetter Oct. 27, 2016, 8:14 a.m. UTC | #3 
On Thu, Oct 27, 2016 at 08:46:50AM +0100, Tvrtko Ursulin wrote:
> 
> On 25/10/2016 13:45, ville.syrjala@linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > Starting from commit b63a16f6cd89 ("drm/i915: Compute display surface
> > offset in the plane check hook for SKL+") we've already rotated the src
> > coordinates by 270 degrees by the time we check if a scaler is needed
> > or not, so we must not account for the rotation a second time.
> > Previously we did these steps in the opposite order and hence the
> > scaler check had to deal with rotation itself. The double rotation
> > handling causes us to enable a scaler pretty much every time 90/270
> > degree plane rotation is requested, leading to fuzzier fonts and whatnot.
> > 
> > Cc: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>
> > Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> > Cc: drm-intel-fixes@lists.freedesktop.org
> > Reported-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> > Fixes: b63a16f6cd89 ("drm/i915: Compute display surface offset in the plane check hook for SKL+")
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_display.c | 14 ++++++++------
> >  1 file changed, 8 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index 5a036999487b..587cd604ce92 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -4671,7 +4671,7 @@ static void cpt_verify_modeset(struct drm_device *dev, int pipe)
> > 
> >  static int
> >  skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
> > -		  unsigned scaler_user, int *scaler_id, unsigned int rotation,
> > +		  unsigned scaler_user, int *scaler_id,
> >  		  int src_w, int src_h, int dst_w, int dst_h)
> >  {
> >  	struct intel_crtc_scaler_state *scaler_state =
> > @@ -4680,9 +4680,12 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
> >  		to_intel_crtc(crtc_state->base.crtc);
> >  	int need_scaling;
> > 
> > -	need_scaling = drm_rotation_90_or_270(rotation) ?
> > -		(src_h != dst_w || src_w != dst_h):
> > -		(src_w != dst_w || src_h != dst_h);
> > +	/*
> > +	 * Src coordinates are already rotated by 270 degrees for
> > +	 * the 90/270 degree plane rotation cases (to match the
> > +	 * GTT mapping), hence no need to account for rotation here.
> > +	 */
> > +	need_scaling = src_w != dst_w || src_h != dst_h;
> > 
> >  	/*
> >  	 * if plane is being disabled or scaler is no more required or force detach
> > @@ -4749,7 +4752,7 @@ int skl_update_scaler_crtc(struct intel_crtc_state *state)
> >  		      intel_crtc->pipe, SKL_CRTC_INDEX);
> > 
> >  	return skl_update_scaler(state, !state->base.active, SKL_CRTC_INDEX,
> > -		&state->scaler_state.scaler_id, DRM_ROTATE_0,
> > +		&state->scaler_state.scaler_id,
> >  		state->pipe_src_w, state->pipe_src_h,
> >  		adjusted_mode->crtc_hdisplay, adjusted_mode->crtc_vdisplay);
> >  }
> > @@ -4783,7 +4786,6 @@ static int skl_update_scaler_plane(struct intel_crtc_state *crtc_state,
> >  	ret = skl_update_scaler(crtc_state, force_detach,
> >  				drm_plane_index(&intel_plane->base),
> >  				&plane_state->scaler_id,
> > -				plane_state->base.rotation,
> >  				drm_rect_width(&plane_state->base.src) >> 16,
> >  				drm_rect_height(&plane_state->base.src) >> 16,
> >  				drm_rect_width(&plane_state->base.dst),
> > 
> 
> Tested-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> 
> After this only the DRM core revert remains. Is that one something of a
> workaround or actually could get in?

We could add an fb_changed boolean to drm_plane_state which drives can use
to override the drm helper's decision whether to call prepare_plane. And
then i915 could set that if rotation changes.

That's probably the fastest quick fix (but won't type that since I'll be
travelling next week).
-Daniel
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5a036999487b..587cd604ce92 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4671,7 +4671,7 @@  static void cpt_verify_modeset(struct drm_device *dev, int pipe)
 
 static int
 skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
-		  unsigned scaler_user, int *scaler_id, unsigned int rotation,
+		  unsigned scaler_user, int *scaler_id,
 		  int src_w, int src_h, int dst_w, int dst_h)
 {
 	struct intel_crtc_scaler_state *scaler_state =
@@ -4680,9 +4680,12 @@  skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
 		to_intel_crtc(crtc_state->base.crtc);
 	int need_scaling;
 
-	need_scaling = drm_rotation_90_or_270(rotation) ?
-		(src_h != dst_w || src_w != dst_h):
-		(src_w != dst_w || src_h != dst_h);
+	/*
+	 * Src coordinates are already rotated by 270 degrees for
+	 * the 90/270 degree plane rotation cases (to match the
+	 * GTT mapping), hence no need to account for rotation here.
+	 */
+	need_scaling = src_w != dst_w || src_h != dst_h;
 
 	/*
 	 * if plane is being disabled or scaler is no more required or force detach
@@ -4749,7 +4752,7 @@  int skl_update_scaler_crtc(struct intel_crtc_state *state)
 		      intel_crtc->pipe, SKL_CRTC_INDEX);
 
 	return skl_update_scaler(state, !state->base.active, SKL_CRTC_INDEX,
-		&state->scaler_state.scaler_id, DRM_ROTATE_0,
+		&state->scaler_state.scaler_id,
 		state->pipe_src_w, state->pipe_src_h,
 		adjusted_mode->crtc_hdisplay, adjusted_mode->crtc_vdisplay);
 }
@@ -4783,7 +4786,6 @@  static int skl_update_scaler_plane(struct intel_crtc_state *crtc_state,
 	ret = skl_update_scaler(crtc_state, force_detach,
 				drm_plane_index(&intel_plane->base),
 				&plane_state->scaler_id,
-				plane_state->base.rotation,
 				drm_rect_width(&plane_state->base.src) >> 16,
 				drm_rect_height(&plane_state->base.src) >> 16,
 				drm_rect_width(&plane_state->base.dst),