On Tue, 06 Jun 2023, Ville Syrjala <[email protected]> wrote: > From: Ville Syrjälä <[email protected]> > > Avoid the locking overhead for DSB registers. We don't need the locks > and intel_dsb_commit() in particular needs to be called from the > vblank evade critical section and thus needs to be fast.
Mmmh, I always find it slightly puzzling to encounter _fw calls in code, wondering what the rationale was, and why we can use the _fw variants. Should we start adding comments explaining why? BR, Jani. > > Signed-off-by: Ville Syrjälä <[email protected]> > --- > drivers/gpu/drm/i915/display/intel_dsb.c | 18 +++++++++--------- > 1 file changed, 9 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c > b/drivers/gpu/drm/i915/display/intel_dsb.c > index bed058d2c3ac..97e593d9f100 100644 > --- a/drivers/gpu/drm/i915/display/intel_dsb.c > +++ b/drivers/gpu/drm/i915/display/intel_dsb.c > @@ -96,7 +96,7 @@ static bool assert_dsb_has_room(struct intel_dsb *dsb) > static bool is_dsb_busy(struct drm_i915_private *i915, enum pipe pipe, > enum dsb_id id) > { > - return intel_de_read(i915, DSB_CTRL(pipe, id)) & DSB_STATUS_BUSY; > + return intel_de_read_fw(i915, DSB_CTRL(pipe, id)) & DSB_STATUS_BUSY; > } > > static void intel_dsb_emit(struct intel_dsb *dsb, u32 ldw, u32 udw) > @@ -243,13 +243,13 @@ void intel_dsb_commit(struct intel_dsb *dsb, bool > wait_for_vblank) > return; > } > > - intel_de_write(dev_priv, DSB_CTRL(pipe, dsb->id), > - (wait_for_vblank ? DSB_WAIT_FOR_VBLANK : 0) | > - DSB_ENABLE); > - intel_de_write(dev_priv, DSB_HEAD(pipe, dsb->id), > - i915_ggtt_offset(dsb->vma)); > - intel_de_write(dev_priv, DSB_TAIL(pipe, dsb->id), > - i915_ggtt_offset(dsb->vma) + tail); > + intel_de_write_fw(dev_priv, DSB_CTRL(pipe, dsb->id), > + (wait_for_vblank ? DSB_WAIT_FOR_VBLANK : 0) | > + DSB_ENABLE); > + intel_de_write_fw(dev_priv, DSB_HEAD(pipe, dsb->id), > + i915_ggtt_offset(dsb->vma)); > + intel_de_write_fw(dev_priv, DSB_TAIL(pipe, dsb->id), > + i915_ggtt_offset(dsb->vma) + tail); > } > > void intel_dsb_wait(struct intel_dsb *dsb) > @@ -266,7 +266,7 @@ void intel_dsb_wait(struct intel_dsb *dsb) > /* Attempt to reset it */ > dsb->free_pos = 0; > dsb->ins_start_offset = 0; > - intel_de_write(dev_priv, DSB_CTRL(pipe, dsb->id), 0); > + intel_de_write_fw(dev_priv, DSB_CTRL(pipe, dsb->id), 0); > } > > /** -- Jani Nikula, Intel Open Source Graphics Center
