diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_cdclk.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_cdclk.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c index d77e2bec1e29..5dc118f26b51 100644 --- a/drivers/gpu/drm/i915/intel_cdclk.c +++ b/drivers/gpu/drm/i915/intel_cdclk.c @@ -1370,10 +1370,15 @@ static void bxt_set_cdclk(struct drm_i915_private *dev_priv, break; } - /* Inform power controller of upcoming frequency change */ + /* + * Inform power controller of upcoming frequency change. BSpec + * requires us to wait up to 150usec, but that leads to timeouts; + * the 2ms used here is based on experiment. + */ mutex_lock(&dev_priv->pcu_lock); - ret = sandybridge_pcode_write(dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ, - 0x80000000); + ret = sandybridge_pcode_write_timeout(dev_priv, + HSW_PCODE_DE_WRITE_FREQ_REQ, + 0x80000000, 2000); mutex_unlock(&dev_priv->pcu_lock); if (ret) { @@ -1404,8 +1409,15 @@ static void bxt_set_cdclk(struct drm_i915_private *dev_priv, I915_WRITE(CDCLK_CTL, val); mutex_lock(&dev_priv->pcu_lock); - ret = sandybridge_pcode_write(dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ, - cdclk_state->voltage_level); + /* + * The timeout isn't specified, the 2ms used here is based on + * experiment. + * FIXME: Waiting for the request completion could be delayed until + * the next PCODE request based on BSpec. + */ + ret = sandybridge_pcode_write_timeout(dev_priv, + HSW_PCODE_DE_WRITE_FREQ_REQ, + cdclk_state->voltage_level, 2000); mutex_unlock(&dev_priv->pcu_lock); if (ret) { |