On Wed, Jul 20, 2016 at 04:59:59PM -0400, Lyude wrote:
Up until now we've actually been making the mistake of leaving the watermark results for each pipe completely blank in skl_compute_wm() when they haven't changed, fix this.
Should this be moved before patch #1? With the existing code we don't try to re-write watermark registers if they aren't changing, so leaving them at zero should be safe. I think we want to make this change before we start re-writing non-dirty watermarks. Alternatively, we could just add the dirty bit test to the appropriate places in patch #1 and not worry about copying over the unchanged values.
Matt
Fixes: 734fa01f3a17 ("drm/i915/gen9: Calculate watermarks during atomic 'check' (v2)") Cc: stable@vger.kernel.org Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: Daniel Vetter daniel.vetter@intel.com Cc: Radhakrishna Sripada radhakrishna.sripada@intel.com Cc: Hans de Goede hdegoede@redhat.com cpaul@redhat.com Cc: Matt Roper matthew.d.roper@intel.com Signed-off-by: Lyude cpaul@redhat.com
drivers/gpu/drm/i915/intel_pm.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index b7d4af1..788db86 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -3987,10 +3987,13 @@ skl_copy_wm_for_pipe(struct skl_wm_values *dst, static int skl_compute_wm(struct drm_atomic_state *state) {
- struct drm_device *dev = state->dev;
- struct drm_i915_private *dev_priv = to_i915(dev); struct drm_crtc *crtc; struct drm_crtc_state *cstate; struct intel_atomic_state *intel_state = to_intel_atomic_state(state); struct skl_wm_values *results = &intel_state->wm_results;
- struct skl_wm_values *hw_wm = &dev_priv->wm.skl_hw; struct skl_pipe_wm *pipe_wm; bool changed = false; int ret, i;
@@ -4039,12 +4042,14 @@ skl_compute_wm(struct drm_atomic_state *state) if (changed) results->dirty_pipes |= drm_crtc_mask(crtc);
if ((results->dirty_pipes & drm_crtc_mask(crtc)) == 0)
if ((results->dirty_pipes & drm_crtc_mask(crtc)) == 0) { /* This pipe's WM's did not change */skl_copy_wm_for_pipe(results, hw_wm, intel_crtc->pipe); continue;}intel_cstate->update_wm_pre = true;
skl_compute_wm_results(crtc->dev, pipe_wm, results, intel_crtc);
skl_compute_wm_results(dev, pipe_wm, results, intel_crtc);}
return 0;
-- 2.7.4