On Wed, Jul 13, 2016 at 11:17:52AM -0700, Matt Roper wrote:
On Wed, Jul 13, 2016 at 09:12:09PM +0300, Ville Syrjälä wrote:
We have wait_for()/_wait_for() for polling stuff.
Those just block until a condition becomes true, right? In this case my understanding from the bspec is that we need to keep re-writing the SAGV disable until it sticks.
the condition is an arbitrary expression such as
static inline bool sagv_disabled(struct drm_i915_private (dev_priv) { u32 tmp;
if (sandybridge_pcode_write(dev_priv, GEN9_PCODE_SAGV_CONTROL, GEN9_SAGV_DISABLE)) goto error;
if (sandybridge_pcode_read(dev_priv, GEN9_PCODE_SAGV_CONTROL, &tmp)) goto error; return tmp & 1;
error: DRM_ERROR("Failed to disable the SAGV\n"); return true; }
ret = wait_for(sagv_disabled(dev_priv), 1); if (ret) DRM_ERROR("Timed out waiting for SAGV to be disabled\n");