diff options
| -rw-r--r-- | Documentation/gpu/i915.rst | 6 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_display.c | 18 |
2 files changed, 24 insertions, 0 deletions
diff --git a/Documentation/gpu/i915.rst b/Documentation/gpu/i915.rst index 33cc6ddf8f64..84ead508f7ad 100644 --- a/Documentation/gpu/i915.rst +++ b/Documentation/gpu/i915.rst @@ -118,6 +118,12 @@ Atomic Plane Helpers .. kernel-doc:: drivers/gpu/drm/i915/display/intel_atomic_plane.c :internal: +Asynchronous Page Flip +---------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/display/intel_display.c + :doc: asynchronous flip implementation + Output Probing -------------- diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c index b23fd5232ee6..a012d48d5e3e 100644 --- a/drivers/gpu/drm/i915/display/intel_display.c +++ b/drivers/gpu/drm/i915/display/intel_display.c @@ -14929,6 +14929,24 @@ static bool intel_cpu_transcoders_need_modeset(struct intel_atomic_state *state, return false; } +/** + * DOC: asynchronous flip implementation + * + * Asynchronous page flip is the implementation for the DRM_MODE_PAGE_FLIP_ASYNC + * flag. Currently async flip is only supported via the drmModePageFlip IOCTL. + * Correspondingly, support is currently added for primary plane only. + * + * Async flip can only change the plane surface address, so anything else + * changing is rejected from the intel_atomic_check_async() function. + * Once this check is cleared, flip done interrupt is enabled using + * the skl_enable_flip_done() function. + * + * As soon as the surface address register is written, flip done interrupt is + * generated and the requested events are sent to the usersapce in the interrupt + * handler itself. The timestamp and sequence sent during the flip done event + * correspond to the last vblank and have no relation to the actual time when + * the flip done event was sent. + */ static int intel_atomic_check_async(struct intel_atomic_state *state) { struct drm_i915_private *i915 = to_i915(state->base.dev); |