drm/i915: update rawclk also on resume

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 would be
intel_modeset_init_hw(), however VLV/CHV need it done before
intel_power_domains_init_hw(). Thus put it there even if it feels
slightly out of place.

v2: Call intel_update_rawclck() in intel_power_domains_init_hw() for all
    platforms (Ville).
Reported-by: Shawn Lee <shawn.c.lee@intel.com>
Cc: Shawn Lee <shawn.c.lee@intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Shawn Lee <shawn.c.lee@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191101142024.13877-1-jani.nikula@intel.com
(cherry picked from commit 59ed05cc)
Cc: <stable@vger.kernel.org> # v4.15+
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/i915/display/intel_display_power.c

@@ -4896,6 +4896,9 @@ 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 */
+	intel_update_rawclk(i915);
+
 	if (INTEL_GEN(i915) >= 11) {
 		icl_display_core_init(i915, resume);
 	} else if (IS_CANNONLAKE(i915)) {

drivers/gpu/drm/i915/i915_drv.c

@@ -364,9 +364,6 @@ static int i915_driver_modeset_probe(struct drm_device *dev)
 	if (ret)
 		goto cleanup_vga_client;
 
-	/* must happen before intel_power_domains_init_hw() on VLV/CHV */
-	intel_update_rawclk(dev_priv);
-
 	intel_power_domains_init_hw(dev_priv, false);
 
 	intel_csr_ucode_init(dev_priv);