Commit 52d006fa authored by Hsin-Yi Wang's avatar Hsin-Yi Wang Committed by Greg Kroah-Hartman

drm/mediatek: call mtk_dsi_stop() after mtk_drm_crtc_atomic_disable()

[ Upstream commit 2458d9d6 ]

mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(), which
needs ovl irq for drm_crtc_wait_one_vblank(), since after mtk_dsi_stop() is
called, ovl irq will be disabled. If drm_crtc_wait_one_vblank() is called
after last irq, it will timeout with this message: "vblank wait timed out
on crtc 0". This happens sometimes when turning off the screen.

In drm_atomic_helper.c#disable_outputs(),
the calling sequence when turning off the screen is:

1. mtk_dsi_encoder_disable()
     --> mtk_output_dsi_disable()
       --> mtk_dsi_stop();  /* sometimes make vblank timeout in
                               atomic_disable */
       --> mtk_dsi_poweroff();
2. mtk_drm_crtc_atomic_disable()
     --> drm_crtc_wait_one_vblank();
     ...
       --> mtk_dsi_ddp_stop()
         --> mtk_dsi_poweroff();

mtk_dsi_poweroff() has reference count design, change to make
mtk_dsi_stop() called in mtk_dsi_poweroff() when refcount is 0.

Fixes: 0707632b ("drm/mediatek: update DSI sub driver flow for sending commands to panel")
Signed-off-by: default avatarHsin-Yi Wang <hsinyi@chromium.org>
Signed-off-by: default avatarCK Hu <ck.hu@mediatek.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 7dd1a64b
......@@ -630,6 +630,15 @@ 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);
if (!mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500)) {
if (dsi->panel) {
if (drm_panel_unprepare(dsi->panel)) {
......@@ -696,7 +705,6 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
}
}
mtk_dsi_stop(dsi);
mtk_dsi_poweroff(dsi);
dsi->enabled = false;
......
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