On Thu, Jun 13, 2019 at 12:24:59PM +0300, Ville Syrjälä wrote:

On Wed, Jun 12, 2019 at 08:24:23PM +0300, Ville Syrjala wrote:

...

From: Ville Syrjälä ville.syrjala@linux.intel.com

We're now calling intel_pipe_config_compare(..., true) uncoditionally which means we're always going clobber the calculated M/N values with the old values if the fuzzy M/N check passes. That causes problems because the fuzzy check allows for a huge difference in the values.

I'm actually tempted to just make the M/N checks exact, but that might prevent fastboot from kicking in when people want it. So for now let's overwrite the computed values with the old values only if decide to skip the modeset.

v2: Copy has_drrs along with M/N M2/N2 values

Cc: stable@vger.kernel.org Cc: Blubberbub@protonmail.com Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Hans de Goede hdegoede@redhat.com Tested-by: Blubberbub@protonmail.com Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110782 Fixes: d19f958db23c ("drm/i915: Enable fastset for non-boot modesets.") Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com

Looks like also https://bugs.freedesktop.org/show_bug.cgi?id=110675

Ok, the copying from old-state to new-state is needed to keep HW/SW state verification later pass, but we want to preserve the calculated state if we'll need to reprogram everything based on that. Makes sense:

Reviewed-by: Imre Deak imre.deak@intel.com

...

---

drivers/gpu/drm/i915/intel_display.c | 36 +++++++++++++++++++++------- 1 file changed, 28 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 1b1ddb48ca7a..3d8ed1cf0ab7 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -12299,9 +12299,6 @@ intel_compare_link_m_n(const struct intel_link_m_n *m_n, m2_n2->gmch_m, m2_n2->gmch_n, !adjust) && intel_compare_m_n(m_n->link_m, m_n->link_n, m2_n2->link_m, m2_n2->link_n, !adjust)) {

• if (adjust)
  

• 	*m2_n2 = *m_n;
  

• return true; }

@@ -13433,6 +13430,33 @@ static int calc_watermark_data(struct intel_atomic_state *state) return 0; } +static void intel_crtc_check_fastset(struct intel_crtc_state *old_crtc_state,

• 		     struct intel_crtc_state *new_crtc_state)
  

+{

• struct drm_i915_private *dev_priv =

• to_i915(new_crtc_state->base.crtc->dev);
  

• if (!intel_pipe_config_compare(dev_priv, old_crtc_state,

• 		       new_crtc_state, true))
  

• return;
  

• new_crtc_state->base.mode_changed = false;
• new_crtc_state->update_pipe = true;
• /*

• * If we're not doing the full modeset we want to
  

• * keep the current M/N values as they may be
  

• * sufficiently different to the computed values
  

• * to cause problems.
  

• *
  

• * FIXME: should really copy more fuzzy state here
  

• */
  

• new_crtc_state->fdi_m_n = old_crtc_state->fdi_m_n;
• new_crtc_state->dp_m_n = old_crtc_state->dp_m_n;
• new_crtc_state->dp_m2_n2 = old_crtc_state->dp_m2_n2;
• new_crtc_state->has_drrs = old_crtc_state->has_drrs;

+}

/**

• intel_atomic_check - validate state object
• @dev: drm device

@@ -13474,11 +13498,7 @@ static int intel_atomic_check(struct drm_device *dev, if (ret) goto fail;

• if (intel_pipe_config_compare(dev_priv, old_crtc_state,
  

• 			      new_crtc_state, true)) {
  

• 	new_crtc_state->base.mode_changed = false;
  

• 	new_crtc_state->update_pipe = true;
  

• }
  

• intel_crtc_check_fastset(old_crtc_state, new_crtc_state);
  

if (needs_modeset(&new_crtc_state->base)) any_ms = true; -- 2.21.0

-- Ville Syrjälä Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx