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authorVille Syrjälä <ville.syrjala@linux.intel.com>2014-06-13 13:37:52 +0300
committerDaniel Vetter <daniel.vetter@ffwll.ch>2014-07-07 11:25:16 +0200
commita877e8015c0d8f308fee925ee72dc6451de616ce (patch)
tree2c32a1bc5895261683712cf8fe42cb02e2d57ff8 /drivers/gpu/drm/i915/intel_display.c
parente37c67a1c5743ac7fc7f946290fee96f84248ca7 (diff)
drm/i915: Wait for cdclk change to occure when going for 400MHz
VLV Punit doesn't support the 400MHz cdclk option, so we bypass the Punit and poke at CCK directly. However we forgot to wait for the frequeency change to complete. Poll the CCK clock status to make sure the clock has changed before we fire up any pipes. Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/i915/intel_display.c')
-rw-r--r--drivers/gpu/drm/i915/intel_display.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index d127e76d81a..251a095acce 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4519,6 +4519,11 @@ static void valleyview_set_cdclk(struct drm_device *dev, int cdclk)
val &= ~DISPLAY_FREQUENCY_VALUES;
val |= divider;
vlv_cck_write(dev_priv, CCK_DISPLAY_CLOCK_CONTROL, val);
+
+ if (wait_for((vlv_cck_read(dev_priv, CCK_DISPLAY_CLOCK_CONTROL) &
+ DISPLAY_FREQUENCY_STATUS) == (divider << DISPLAY_FREQUENCY_STATUS_SHIFT),
+ 50))
+ DRM_ERROR("timed out waiting for CDclk change\n");
mutex_unlock(&dev_priv->dpio_lock);
}