[Intel-gfx] [PATCH] drm/i915: update rawclk also on resume

[Jani Nikula]

Since CNP it's possible for rawclk to have two different values, 19.2
and 24 MHz. If the value indicated by SFUSE_STRAP register is different
from the power on default for PCH_RAWCLK_FREQ, we'll end up having a
mismatch between the rawclk hardware and software states after
suspend/resume. On previous platforms this used to work by accident,
because the power on defaults worked just fine.

Update the rawclk also on resume. The natural place to do this is
intel_modeset_init_hw(), however VLV/CHV need it done before
intel_power_domains_init_hw(). Split the update accordingly, even if
that's slighly ugly. This means moving the update later for non-VLV/CHV
platforms in probe.

Reported-by: Shawn Lee <shawn.c.lee at intel.com>
Cc: Shawn Lee <shawn.c.lee at intel.com>
Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c       | 5 +++++
 drivers/gpu/drm/i915/display/intel_display_power.c | 7 +++++++
 drivers/gpu/drm/i915/i915_drv.c                    | 3 ---
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index e56a75c07043..e31697fdffd3 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -16610,6 +16610,11 @@ void intel_init_display_hooks(struct drm_i915_private *dev_priv)
 
 void intel_modeset_init_hw(struct drm_i915_private *i915)
 {
+	/*
+	 * VLV/CHV update rawclk earlier in intel_power_domains_init_hw().
+	 */
+	if (!IS_VALLEYVIEW(i915) && !IS_CHERRYVIEW(i915))
+		intel_update_rawclk(i915);
 	intel_update_cdclk(i915);
 	intel_dump_cdclk_state(&i915->cdclk.hw, "Current CDCLK");
 	i915->cdclk.logical = i915->cdclk.actual = i915->cdclk.hw;
diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
index 707ac110e271..999133d1f088 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power.c
+++ b/drivers/gpu/drm/i915/display/intel_display_power.c
@@ -5015,6 +5015,13 @@ void intel_power_domains_init_hw(struct drm_i915_private *i915, bool resume)
 
 	power_domains->initializing = true;
 
+	/*
+	 * Must happen before power domain init on VLV/CHV, the rest update
+	 * rawclk later in intel_modeset_init_hw().
+	 */
+	if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))
+		intel_update_rawclk(i915);
+
 	if (INTEL_GEN(i915) >= 11) {
 		icl_display_core_init(i915, resume);
 	} else if (IS_CANNONLAKE(i915)) {
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 21273b516dbe..62906336298a 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -296,9 +296,6 @@ static int i915_driver_modeset_probe(struct drm_i915_private *i915)
 	if (ret)
 		goto cleanup_vga_client;
 
-	/* must happen before intel_power_domains_init_hw() on VLV/CHV */
-	intel_update_rawclk(i915);
-
 	intel_power_domains_init_hw(i915, false);
 
 	intel_csr_ucode_init(i915);
-- 
2.20.1