All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH] drm/mediatek: dsi: Move mtk_dsi_stop() call back to mtk_dsi_poweroff()
@ 2022-08-04 19:43 ` Nícolas F. R. A. Prado
  0 siblings, 0 replies; 12+ messages in thread
From: Nícolas F. R. A. Prado @ 2022-08-04 19:43 UTC (permalink / raw)
  To: Chun-Kuang Hu
  Cc: AngeloGioacchino Del Regno, kernel, Nícolas F. R. A. Prado,
	Daniel Vetter, David Airlie, Jitao Shi, Matthias Brugger,
	Philipp Zabel, Rex-BC Chen, Xinlei Lee, dri-devel,
	linux-arm-kernel, linux-kernel, linux-mediatek

As the comment right before the mtk_dsi_stop() call advises,
mtk_dsi_stop() should only be called after
mtk_drm_crtc_atomic_disable(). That's because that function calls
drm_crtc_wait_one_vblank(), which requires the vblank irq to be enabled.

Previously mtk_dsi_stop(), being in mtk_dsi_poweroff() and guarded by a
refcount, would only be called at the end of
mtk_drm_crtc_atomic_disable(), through the call to mtk_crtc_ddp_hw_fini().
Commit cde7e2e35c28 ("drm/mediatek: Separate poweron/poweroff from
enable/disable and define new funcs") moved the mtk_dsi_stop() call to
mtk_output_dsi_disable(), causing it to be called before
mtk_drm_crtc_atomic_disable(), and consequently generating vblank
timeout warnings during suspend.

Move the mtk_dsi_stop() call back to mtk_dsi_poweroff() so that we have
a working vblank irq during mtk_drm_crtc_atomic_disable() and stop
getting vblank timeout warnings.

Fixes: cde7e2e35c28 ("drm/mediatek: Separate poweron/poweroff from enable/disable and define new funcs")
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>

---

 drivers/gpu/drm/mediatek/mtk_dsi.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 9cc406e1eee1..f8ad59771551 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -685,6 +685,16 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
 	if (--dsi->refcount != 0)
 		return;
 
+	/*
+	 * mtk_dsi_stop() and mtk_dsi_start() is asymmetric, since
+	 * mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(),
+	 * which needs irq for vblank, and mtk_dsi_stop() will disable irq.
+	 * mtk_dsi_start() needs to be called in mtk_output_dsi_enable(),
+	 * after dsi is fully set.
+	 */
+	mtk_dsi_stop(dsi);
+
+	mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500);
 	mtk_dsi_reset_engine(dsi);
 	mtk_dsi_lane0_ulp_mode_enter(dsi);
 	mtk_dsi_clk_ulp_mode_enter(dsi);
@@ -735,17 +745,6 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
 	if (!dsi->enabled)
 		return;
 
-	/*
-	 * mtk_dsi_stop() and mtk_dsi_start() is asymmetric, since
-	 * mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(),
-	 * which needs irq for vblank, and mtk_dsi_stop() will disable irq.
-	 * mtk_dsi_start() needs to be called in mtk_output_dsi_enable(),
-	 * after dsi is fully set.
-	 */
-	mtk_dsi_stop(dsi);
-
-	mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500);
-
 	dsi->enabled = false;
 }
 
-- 
2.37.1


^ permalink raw reply related	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2022-09-21 10:48 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-08-04 19:43 [PATCH] drm/mediatek: dsi: Move mtk_dsi_stop() call back to mtk_dsi_poweroff() Nícolas F. R. A. Prado
2022-08-04 19:43 ` Nícolas F. R. A. Prado
2022-08-04 19:43 ` Nícolas F. R. A. Prado
2022-09-19  8:40 ` Hsin-Yi Wang
2022-09-19  8:40   ` Hsin-Yi Wang
2022-09-19  8:40   ` Hsin-Yi Wang
2022-09-19 13:32   ` AngeloGioacchino Del Regno
2022-09-19 13:32     ` AngeloGioacchino Del Regno
2022-09-19 13:32     ` AngeloGioacchino Del Regno
2022-09-21  8:49     ` Allen-KH Cheng
2022-09-21  8:49       ` Allen-KH Cheng
2022-09-21  8:49       ` Allen-KH Cheng

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.