[Intel-gfx] [PATCH] drm/i915: Fix issues caused from get_clock elimination

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

For non-PCH encoders ironlake_crtc_clock_get() attempts to extract
adjusted_mode.clock from port_clock. But now that we call
ironlake_crtc_clock_get() before the encoders' get_config() that no
longer works.

To fix the problem also call ironlake_crtc_clock_get() before
get_config() for PCH encoders, and afterwards for non-PCH encoders.
Also be careful not to clobber port_clock when calling it afterwards.

The problem was introduced by:
"drm/i915: Fix port_clock readout for SDVO and HDMI 12bpc cases"

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---

This could be squashed with the patch that caused the problem in the first
place, but I left it separate for now to solicit feedback on how ugly do
people think this is. I could of course leave the get_clock callback
in place, but only fill it in for ILK+ and add a has_pch_encoder check
there, otherwise we could keep the direct func call in get_pipe_config.

 drivers/gpu/drm/i915/intel_display.c | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5b8a437..3cfd99b 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6040,7 +6040,14 @@ static void ironlake_crtc_clock_get(struct intel_crtc *crtc,
 	 * This value does not include pixel_multiplier. We will fix
 	 * port_clock in the encoder's get_config() function if necessary.
 	 */
-	pipe_config->port_clock = pipe_config->adjusted_mode.clock = clock;
+	pipe_config->adjusted_mode.clock = clock;
+
+	/*
+	 * We get called before encoder get_config() for pch encoders,
+	 * after for non-pch. Don't clobber port_clock in the latter case.
+	 */
+	if (!pipe_config->port_clock)
+		pipe_config->port_clock = clock;
 }
 
 static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
@@ -6105,6 +6112,8 @@ static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
 		pipe_config->pixel_multiplier =
 			((tmp & PLL_REF_SDVO_HDMI_MULTIPLIER_MASK)
 			 >> PLL_REF_SDVO_HDMI_MULTIPLIER_SHIFT) + 1;
+
+		ironlake_crtc_clock_get(crtc, pipe_config);
 	} else {
 		pipe_config->pixel_multiplier = 1;
 	}
@@ -6113,8 +6122,6 @@ static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
 
 	ironlake_get_pfit_config(crtc, pipe_config);
 
-	ironlake_crtc_clock_get(crtc, pipe_config);
-
 	return true;
 }
 
@@ -8827,6 +8834,9 @@ check_crtc_state(struct drm_device *dev)
 				encoder->get_config(encoder, &pipe_config);
 		}
 
+		if (HAS_PCH_SPLIT(dev) && !pipe_config.has_pch_encoder)
+			ironlake_crtc_clock_get(crtc, &pipe_config);
+
 		WARN(crtc->active != active,
 		     "crtc active state doesn't match with hw state "
 		     "(expected %i, found %i)\n", crtc->active, active);
@@ -10479,6 +10489,13 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
 			      pipe);
 	}
 
+	if (HAS_PCH_SPLIT(dev)) {
+		list_for_each_entry(crtc, &dev->mode_config.crtc_list, base.head) {
+			if (!crtc->config.has_pch_encoder)
+				ironlake_crtc_clock_get(crtc, &crtc->config);
+		}
+	}
+
 	list_for_each_entry(connector, &dev->mode_config.connector_list,
 			    base.head) {
 		if (connector->get_hw_state(connector)) {
-- 
1.8.1.5