To properly implement atomic w/ runtime pm, we move drm_atomic_helper_commit_modeset_enables() above drm_atomic_helper_commit_planes() to ensure CRTCs are enabled before modifying plane registers, and set active_only to true to filter out plane update notifications when the CRTC is disabled.
According to the document from linux kernel: Set the active_only parameters to true in order not to receive plane update notifications related to a disabled CRTC. This avoids the need to manually ignore plane updates in driver code when the driver and/or hardware can't or just don't need to deal with updates on disabled CRTCs, for example when supporting runtime PM.
Signed-off-by: Bibby Hsieh bibby.hsieh@mediatek.com Signed-off-by: Daniel Kurtz djkurtz@chromium.org --- drivers/gpu/drm/mediatek/mtk_drm_drv.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c index b1223d5..507392a 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c @@ -61,10 +61,25 @@ static void mtk_atomic_complete(struct mtk_drm_private *private,
mtk_atomic_wait_for_fences(state);
+ /* + * Mediatek drm supports runtime PM, so plane registers cannot be + * written when their crtc is disabled. + * + * The comment for drm_atomic_helper_commit states: + * For drivers supporting runtime PM the recommended sequence is + * + * drm_atomic_helper_commit_modeset_disables(dev, state); + * drm_atomic_helper_commit_modeset_enables(dev, state); + * drm_atomic_helper_commit_planes(dev, state, true); + * + * See the kerneldoc entries for these three functions for more details. + */ drm_atomic_helper_commit_modeset_disables(drm, state); - drm_atomic_helper_commit_planes(drm, state, false); drm_atomic_helper_commit_modeset_enables(drm, state); + drm_atomic_helper_commit_planes(drm, state, true); + drm_atomic_helper_wait_for_vblanks(drm, state); + drm_atomic_helper_cleanup_planes(drm, state); drm_atomic_state_free(state); }