[Intel-gfx] [PATCH 04/10] drm/i915: Always read out M2_N2 in intel_cpu_transcoder_get_m_n

[Maarten Lankhorst]

has_drrs is a flag we can't read out. We set it when seamless DRRS is
enabled in pipe_config, so intel_dump_pipe_config() and
intel_pipe_config_compare() will continue to do the right thing when
has_drrs is set on the real state.

This removes one more dereference of crtc->config.
While at it, fixup the comment and also read out M2_N2 for CHV, since
we program it in the set_m_n function.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index bb16a9acf117..7812fab31646 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6893,8 +6893,8 @@ static void intel_cpu_transcoder_set_m_n(const struct intel_crtc_state *crtc_sta
 		I915_WRITE(PIPE_LINK_M1(transcoder), m_n->link_m);
 		I915_WRITE(PIPE_LINK_N1(transcoder), m_n->link_n);
 		/* M2_N2 registers to be set only for gen < 8 (M2_N2 available
-		 * for gen < 8) and if DRRS is supported (to make sure the
-		 * registers are not unnecessarily accessed).
+		 * for gen < 8 and CHV) and if DRRS is supported (to make sure
+		 * the registers are not unnecessarily accessed).
 		 */
 		if (m2_n2 && (IS_CHERRYVIEW(dev_priv) ||
 		    INTEL_GEN(dev_priv) < 8) && crtc_state->has_drrs) {
@@ -8747,11 +8747,10 @@ static void intel_cpu_transcoder_get_m_n(struct intel_crtc *crtc,
 		m_n->tu = ((I915_READ(PIPE_DATA_M1(transcoder))
 			    & TU_SIZE_MASK) >> TU_SIZE_SHIFT) + 1;
 		/* Read M2_N2 registers only for gen < 8 (M2_N2 available for
-		 * gen < 8) and if DRRS is supported (to make sure the
-		 * registers are not unnecessarily read).
+		 * gen < 8 and CHV).
 		 */
-		if (m2_n2 && INTEL_GEN(dev_priv) < 8 &&
-			crtc->config->has_drrs) {
+		if (m2_n2 && (INTEL_GEN(dev_priv) < 8 ||
+			      IS_CHERRYVIEW(dev_priv))) {
 			m2_n2->link_m = I915_READ(PIPE_LINK_M2(transcoder));
 			m2_n2->link_n =	I915_READ(PIPE_LINK_N2(transcoder));
 			m2_n2->gmch_m =	I915_READ(PIPE_DATA_M2(transcoder))
-- 
2.19.0