2022-08-04 19:48:23

by Nícolas F. R. A. Prado

[permalink] [raw]
Subject: [PATCH] drm/mediatek: dsi: Move mtk_dsi_stop() call back to mtk_dsi_poweroff()

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 <[email protected]>

---

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



2022-09-19 09:11:21

by Hsin-Yi Wang

[permalink] [raw]
Subject: Re: [PATCH] drm/mediatek: dsi: Move mtk_dsi_stop() call back to mtk_dsi_poweroff()

On Mon, Sep 19, 2022 at 4:39 PM Nícolas F. R. A. Prado
<[email protected]> wrote:
>
> 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 <[email protected]>
>
Tested-by: Hsin-Yi Wang <[email protected]>

Tested on mt8183 jacuzzi and mt8186 that this patch fixes the vblank warning.

> ---
>
> 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
>

Subject: Re: [PATCH] drm/mediatek: dsi: Move mtk_dsi_stop() call back to mtk_dsi_poweroff()

Il 19/09/22 10:40, Hsin-Yi Wang ha scritto:
> On Mon, Sep 19, 2022 at 4:39 PM Nícolas F. R. A. Prado
> <[email protected]> wrote:
>>
>> 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 <[email protected]>
>>
> Tested-by: Hsin-Yi Wang <[email protected]>
>

Reviewed-by: AngeloGioacchino Del Regno <[email protected]>

2022-09-21 08:59:29

by Allen-KH Cheng

[permalink] [raw]
Subject: Re: [PATCH] drm/mediatek: dsi: Move mtk_dsi_stop() call back to mtk_dsi_poweroff()



On 9/19/22 21:32, AngeloGioacchino Del Regno wrote:
> Il 19/09/22 10:40, Hsin-Yi Wang ha scritto:
>> On Mon, Sep 19, 2022 at 4:39 PM Nícolas F. R. A. Prado
>> <[email protected]> wrote:
>>>
>>> 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 <[email protected]>
>>>
>> Tested-by: Hsin-Yi Wang <[email protected]>
>>
>
> Reviewed-by: AngeloGioacchino Del Regno
> <[email protected]>
>
>

Tested suspend/resume work properly on mt8188 and mt8186 .

Tested-by: Allen-KH Cheng <[email protected]>