Moving the wait to a helper allows callers outside of the core to wait for pending updates to complete.
This can be used to prevent races against nonblocking modesets. Only the hw_done call in swap_state is moved to a helper, doing it for the other callers requires too many changes and I think this is the only useful one to export.
Signed-off-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com --- drivers/gpu/drm/drm_atomic_helper.c | 51 +++++++++++++++++++++++++++---------- include/drm/drm_atomic_helper.h | 1 + 2 files changed, 38 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 86d3093c6c9b..1b068ce1aea9 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -2067,6 +2067,41 @@ void drm_atomic_helper_cleanup_planes(struct drm_device *dev, EXPORT_SYMBOL(drm_atomic_helper_cleanup_planes);
/** + * drm_atomic_helper_wait_for_hw_done - wait for all previous hw updates to complete. + * @crtc: crtc to wait on. + * + * This function waits for all previous hardware updates queued on @crtc + * to complete. + * + * Returns: + * 0 on success, negative error code on failure. + */ +int drm_atomic_helper_wait_for_hw_done(struct drm_crtc *crtc) +{ + struct drm_crtc_commit *commit; + long ret; + + spin_lock(&crtc->commit_lock); + commit = list_first_entry_or_null(&crtc->commit_list, + struct drm_crtc_commit, commit_entry); + if (commit) + drm_crtc_commit_get(commit); + spin_unlock(&crtc->commit_lock); + + if (!commit) + return 0; + + ret = wait_for_completion_timeout(&commit->hw_done, 10 * HZ); + drm_crtc_commit_put(commit); + + if (ret == 0) + return -EBUSY; + + return ret > 0 ? 0 : ret; +} +EXPORT_SYMBOL(drm_atomic_helper_wait_for_hw_done); + +/** * drm_atomic_helper_swap_state - store atomic state into current sw state * @state: atomic state * @stall: stall for proceeding commits @@ -2107,28 +2142,16 @@ void drm_atomic_helper_swap_state(struct drm_atomic_state *state, struct drm_crtc_state *old_crtc_state, *new_crtc_state; struct drm_plane *plane; struct drm_plane_state *old_plane_state, *new_plane_state; - struct drm_crtc_commit *commit; void *obj, *obj_state; const struct drm_private_state_funcs *funcs;
if (stall) { for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) { - spin_lock(&crtc->commit_lock); - commit = list_first_entry_or_null(&crtc->commit_list, - struct drm_crtc_commit, commit_entry); - if (commit) - drm_crtc_commit_get(commit); - spin_unlock(&crtc->commit_lock); + ret = drm_atomic_helper_wait_for_hw_done(crtc);
- if (!commit) - continue; - - ret = wait_for_completion_timeout(&commit->hw_done, - 10*HZ); - if (ret == 0) + if (ret < 0) DRM_ERROR("[CRTC:%d:%s] hw_done timed out\n", crtc->base.id, crtc->name); - drm_crtc_commit_put(commit); } }
diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h index f0a8678ae98e..175a1a3fed36 100644 --- a/include/drm/drm_atomic_helper.h +++ b/include/drm/drm_atomic_helper.h @@ -77,6 +77,7 @@ void drm_atomic_helper_disable_planes_on_crtc(struct drm_crtc_state *old_crtc_state, bool atomic);
+int drm_atomic_helper_wait_for_hw_done(struct drm_crtc *crtc); void drm_atomic_helper_swap_state(struct drm_atomic_state *state, bool stall);