Hi, Hsin-yi:
On Thu, 2019-03-21 at 09:28 +0800, CK Hu wrote:
> Hi, Hsin-yi:
>
> On Wed, 2019-03-20 at 15:18 +0800, Hsin-Yi Wang wrote:
> > 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: 0707632b5bac ("drm/mediatek: update DSI sub driver flow for sending
> > commands to panel")
> > Signed-off-by: Hsin-Yi Wang <hsi...@chromium.org>
> > ---
> > change log:
> > v1->v2:
> > * update commit message.
> > * call mtk_dsi_stop() in mtk_dsi_poweroff() when refcount is 0.
> > ---
> > drivers/gpu/drm/mediatek/mtk_dsi.c | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c
> > b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > index b00eb2d2e086..e152f37af57d 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > @@ -630,6 +630,8 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
> > if (--dsi->refcount != 0)
> > return;
> >
> > + 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)) {
>
> I think you just move mtk_dsi_stop() into mtk_dsi_poweroff() would works
> fine, but I would rather like calling mtk_dsi_start() and mtk_dsi_stop()
> in a symmetric manner. That means you may also move below functions into
> mtk_dsi_poweron():
>
> mtk_dsi_set_mode(dsi);
> mtk_dsi_clk_hs_mode(dsi, 1);
> mtk_dsi_start(dsi);
>
>
> > @@ -696,7 +698,6 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
> > }
> > }
> >
> > - mtk_dsi_stop(dsi);
> > mtk_dsi_poweroff(dsi);
> >
> > dsi->enabled = false;
> > @@ -1178,6 +1179,8 @@ static int mtk_dsi_remove(struct platform_device
> > *pdev)
> > struct mtk_dsi *dsi = platform_get_drvdata(pdev);
> >
> > mtk_output_dsi_disable(dsi);
> > + mtk_dsi_stop(dsi);
> > + mtk_dsi_poweroff(dsi);
>
> I think mtk_output_dsi_disable() would call mtk_dsi_poweroff(), and
> mtk_dsi_poweroff() would call mtk_dsi_stop(), so these two line are
> redundant. And I think you should remove mtk_dsi_stop() in
> mtk_output_dsi_disable(), why not in this patch?
You've removed mtk_dsi_stop() in mtk_output_dsi_disable(), I just miss
it, sorry for this.
Regards,
CK
>
> Regards,
> CK
>
> > component_del(&pdev->dev, &mtk_dsi_component_ops);
> >
> > return 0;
>
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