From mboxrd@z Thu Jan 1 00:00:00 1970 From: bibby.hsieh@mediatek.com (Bibby Hsieh) Date: Fri, 29 Jul 2016 17:04:14 +0800 Subject: [PATCH 7/7] drm/mediatek: Fix mtk_atomic_complete for runtime_pm In-Reply-To: <1469783054-54567-1-git-send-email-bibby.hsieh@mediatek.com> References: <1469783054-54567-1-git-send-email-bibby.hsieh@mediatek.com> Message-ID: <1469783054-54567-8-git-send-email-bibby.hsieh@mediatek.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 Signed-off-by: Daniel Kurtz --- 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); } -- 1.7.9.5