* [PATCH v2] drm/komeda: Workaround for broken FLIP_COMPLETE timestamps
@ 2019-09-23 10:10 ` Mihail Atanassov
0 siblings, 0 replies; 11+ messages in thread
From: Mihail Atanassov @ 2019-09-23 10:10 UTC (permalink / raw)
To: dri-devel@lists.freedesktop.org
Cc: Mihail Atanassov, nd, Maarten Lankhorst, Maxime Ripard, Sean Paul,
Daniel Vetter, Liviu Dudau,
james qian wang (Arm Technology China), Liviu Dudau,
Brian Starkey, David Airlie, linux-kernel@vger.kernel.org
When initially turning a crtc on, drm_reset_vblank_timestamp will
set the vblank timestamp to 0 for any driver that doesn't provide
a ->get_vblank_timestamp() hook.
Unfortunately, the FLIP_COMPLETE event depends on that timestamp,
and the only way to regenerate a valid one is to have vblank
interrupts enabled and have a valid in-ISR call to
drm_crtc_handle_vblank.
Additionally, if the user doesn't request vblanks but _does_ request
FLIP_COMPLETE events, we still don't have a good timestamp: it'll be the
same stamp as the last vblank one.
Work around the issue by always enabling vblanks when the CRTC is on.
Reducing the amount of time that PL0 has to be unmasked would be nice to
fix at a later time.
Changes since v1 [https://patchwork.freedesktop.org/patch/331727/]:
- moved drm_crtc_vblank_put call to the ->atomic_disable() hook
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
---
drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
index 34bc73ca18bc..d06679afb228 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
@@ -489,6 +489,7 @@ komeda_crtc_atomic_enable(struct drm_crtc *crtc,
pm_runtime_get_sync(crtc->dev->dev);
komeda_crtc_prepare(to_kcrtc(crtc));
drm_crtc_vblank_on(crtc);
+ WARN_ON(drm_crtc_vblank_get(crtc));
komeda_crtc_do_flush(crtc, old);
}
@@ -581,6 +582,7 @@ komeda_crtc_atomic_disable(struct drm_crtc *crtc,
komeda_crtc_flush_and_wait_for_flip_done(kcrtc, disable_done);
}
+ drm_crtc_vblank_put(crtc);
drm_crtc_vblank_off(crtc);
komeda_crtc_unprepare(kcrtc);
pm_runtime_put(crtc->dev->dev);
--
2.23.0
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [v2] drm/komeda: Workaround for broken FLIP_COMPLETE timestamps
2019-09-23 10:10 ` Mihail Atanassov
@ 2019-09-29 6:18 ` james qian wang (Arm Technology China)
-1 siblings, 0 replies; 11+ messages in thread
From: james qian wang (Arm Technology China) @ 2019-09-29 6:18 UTC (permalink / raw)
To: Mihail Atanassov
Cc: Maxime Ripard, Liviu Dudau, linux-kernel@vger.kernel.org,
dri-devel@lists.freedesktop.org, David Airlie, nd, Sean Paul
On Mon, Sep 23, 2019 at 10:10:26AM +0000, Mihail Atanassov wrote:
> When initially turning a crtc on, drm_reset_vblank_timestamp will
> set the vblank timestamp to 0 for any driver that doesn't provide
> a ->get_vblank_timestamp() hook.
>
> Unfortunately, the FLIP_COMPLETE event depends on that timestamp,
> and the only way to regenerate a valid one is to have vblank
> interrupts enabled and have a valid in-ISR call to
> drm_crtc_handle_vblank.
>
> Additionally, if the user doesn't request vblanks but _does_ request
> FLIP_COMPLETE events, we still don't have a good timestamp: it'll be the
> same stamp as the last vblank one.
>
> Work around the issue by always enabling vblanks when the CRTC is on.
> Reducing the amount of time that PL0 has to be unmasked would be nice to
> fix at a later time.
>
> Changes since v1 [https://patchwork.freedesktop.org/patch/331727/]:
> - moved drm_crtc_vblank_put call to the ->atomic_disable() hook
>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: Liviu Dudau <Liviu.Dudau@arm.com>
> Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
> ---
> drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> index 34bc73ca18bc..d06679afb228 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> @@ -489,6 +489,7 @@ komeda_crtc_atomic_enable(struct drm_crtc *crtc,
> pm_runtime_get_sync(crtc->dev->dev);
> komeda_crtc_prepare(to_kcrtc(crtc));
> drm_crtc_vblank_on(crtc);
> + WARN_ON(drm_crtc_vblank_get(crtc));
> komeda_crtc_do_flush(crtc, old);
> }
>
> @@ -581,6 +582,7 @@ komeda_crtc_atomic_disable(struct drm_crtc *crtc,
> komeda_crtc_flush_and_wait_for_flip_done(kcrtc, disable_done);
> }
>
> + drm_crtc_vblank_put(crtc);
> drm_crtc_vblank_off(crtc);
> komeda_crtc_unprepare(kcrtc);
> pm_runtime_put(crtc->dev->dev);
Looks good to me.
Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [v2] drm/komeda: Workaround for broken FLIP_COMPLETE timestamps
@ 2019-09-29 6:18 ` james qian wang (Arm Technology China)
0 siblings, 0 replies; 11+ messages in thread
From: james qian wang (Arm Technology China) @ 2019-09-29 6:18 UTC (permalink / raw)
To: Mihail Atanassov
Cc: dri-devel@lists.freedesktop.org, Maxime Ripard, Liviu Dudau,
linux-kernel@vger.kernel.org, David Airlie, nd, Sean Paul
On Mon, Sep 23, 2019 at 10:10:26AM +0000, Mihail Atanassov wrote:
> When initially turning a crtc on, drm_reset_vblank_timestamp will
> set the vblank timestamp to 0 for any driver that doesn't provide
> a ->get_vblank_timestamp() hook.
>
> Unfortunately, the FLIP_COMPLETE event depends on that timestamp,
> and the only way to regenerate a valid one is to have vblank
> interrupts enabled and have a valid in-ISR call to
> drm_crtc_handle_vblank.
>
> Additionally, if the user doesn't request vblanks but _does_ request
> FLIP_COMPLETE events, we still don't have a good timestamp: it'll be the
> same stamp as the last vblank one.
>
> Work around the issue by always enabling vblanks when the CRTC is on.
> Reducing the amount of time that PL0 has to be unmasked would be nice to
> fix at a later time.
>
> Changes since v1 [https://patchwork.freedesktop.org/patch/331727/]:
> - moved drm_crtc_vblank_put call to the ->atomic_disable() hook
>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: Liviu Dudau <Liviu.Dudau@arm.com>
> Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
> ---
> drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> index 34bc73ca18bc..d06679afb228 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> @@ -489,6 +489,7 @@ komeda_crtc_atomic_enable(struct drm_crtc *crtc,
> pm_runtime_get_sync(crtc->dev->dev);
> komeda_crtc_prepare(to_kcrtc(crtc));
> drm_crtc_vblank_on(crtc);
> + WARN_ON(drm_crtc_vblank_get(crtc));
> komeda_crtc_do_flush(crtc, old);
> }
>
> @@ -581,6 +582,7 @@ komeda_crtc_atomic_disable(struct drm_crtc *crtc,
> komeda_crtc_flush_and_wait_for_flip_done(kcrtc, disable_done);
> }
>
> + drm_crtc_vblank_put(crtc);
> drm_crtc_vblank_off(crtc);
> komeda_crtc_unprepare(kcrtc);
> pm_runtime_put(crtc->dev->dev);
Looks good to me.
Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH v2 RESEND] drm/komeda: Workaround for broken FLIP_COMPLETE timestamps
2019-09-23 10:10 ` Mihail Atanassov
@ 2019-10-01 14:21 ` Mihail Atanassov
-1 siblings, 0 replies; 11+ messages in thread
From: Mihail Atanassov @ 2019-10-01 14:21 UTC (permalink / raw)
To: dri-devel@lists.freedesktop.org
Cc: Mihail Atanassov, David Airlie, Liviu Dudau,
linux-kernel@vger.kernel.org,
james qian wang (Arm Technology China), nd
When initially turning a crtc on, drm_reset_vblank_timestamp will
set the vblank timestamp to 0 for any driver that doesn't provide
a ->get_vblank_timestamp() hook.
Unfortunately, the FLIP_COMPLETE event depends on that timestamp,
and the only way to regenerate a valid one is to have vblank
interrupts enabled and have a valid in-ISR call to
drm_crtc_handle_vblank.
Additionally, if the user doesn't request vblanks but _does_ request
FLIP_COMPLETE events, we still don't have a good timestamp: it'll be the
same stamp as the last vblank one.
Work around the issue by always enabling vblanks when the CRTC is on.
Reducing the amount of time that PL0 has to be unmasked would be nice to
fix at a later time.
Changes since v1 [https://patchwork.freedesktop.org/patch/331727/]:
- moved drm_crtc_vblank_put call to the ->atomic_disable() hook
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
---
drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
index 9ca5dbfd0723..75263d8cd0bd 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
@@ -249,6 +249,7 @@ komeda_crtc_atomic_enable(struct drm_crtc *crtc,
{
komeda_crtc_prepare(to_kcrtc(crtc));
drm_crtc_vblank_on(crtc);
+ WARN_ON(drm_crtc_vblank_get(crtc));
komeda_crtc_do_flush(crtc, old);
}
@@ -341,6 +342,7 @@ komeda_crtc_atomic_disable(struct drm_crtc *crtc,
komeda_crtc_flush_and_wait_for_flip_done(kcrtc, disable_done);
}
+ drm_crtc_vblank_put(crtc);
drm_crtc_vblank_off(crtc);
komeda_crtc_unprepare(kcrtc);
}
--
2.23.0
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v2 RESEND] drm/komeda: Workaround for broken FLIP_COMPLETE timestamps
@ 2019-10-01 14:21 ` Mihail Atanassov
0 siblings, 0 replies; 11+ messages in thread
From: Mihail Atanassov @ 2019-10-01 14:21 UTC (permalink / raw)
To: dri-devel@lists.freedesktop.org
Cc: Mihail Atanassov, nd, Daniel Vetter, Liviu Dudau,
james qian wang (Arm Technology China), Liviu Dudau,
Brian Starkey, David Airlie, linux-kernel@vger.kernel.org
When initially turning a crtc on, drm_reset_vblank_timestamp will
set the vblank timestamp to 0 for any driver that doesn't provide
a ->get_vblank_timestamp() hook.
Unfortunately, the FLIP_COMPLETE event depends on that timestamp,
and the only way to regenerate a valid one is to have vblank
interrupts enabled and have a valid in-ISR call to
drm_crtc_handle_vblank.
Additionally, if the user doesn't request vblanks but _does_ request
FLIP_COMPLETE events, we still don't have a good timestamp: it'll be the
same stamp as the last vblank one.
Work around the issue by always enabling vblanks when the CRTC is on.
Reducing the amount of time that PL0 has to be unmasked would be nice to
fix at a later time.
Changes since v1 [https://patchwork.freedesktop.org/patch/331727/]:
- moved drm_crtc_vblank_put call to the ->atomic_disable() hook
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
---
drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
index 9ca5dbfd0723..75263d8cd0bd 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
@@ -249,6 +249,7 @@ komeda_crtc_atomic_enable(struct drm_crtc *crtc,
{
komeda_crtc_prepare(to_kcrtc(crtc));
drm_crtc_vblank_on(crtc);
+ WARN_ON(drm_crtc_vblank_get(crtc));
komeda_crtc_do_flush(crtc, old);
}
@@ -341,6 +342,7 @@ komeda_crtc_atomic_disable(struct drm_crtc *crtc,
komeda_crtc_flush_and_wait_for_flip_done(kcrtc, disable_done);
}
+ drm_crtc_vblank_put(crtc);
drm_crtc_vblank_off(crtc);
komeda_crtc_unprepare(kcrtc);
}
--
2.23.0
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH v2 RESEND] drm/komeda: Workaround for broken FLIP_COMPLETE timestamps
2019-10-01 14:21 ` Mihail Atanassov
(?)
@ 2019-10-01 14:42 ` Ayan Halder
-1 siblings, 0 replies; 11+ messages in thread
From: Ayan Halder @ 2019-10-01 14:42 UTC (permalink / raw)
To: Mihail Atanassov
Cc: dri-devel@lists.freedesktop.org, David Airlie, Liviu Dudau,
linux-kernel@vger.kernel.org,
james qian wang (Arm Technology China), nd
On Tue, Oct 01, 2019 at 02:21:40PM +0000, Mihail Atanassov wrote:
> When initially turning a crtc on, drm_reset_vblank_timestamp will
> set the vblank timestamp to 0 for any driver that doesn't provide
> a ->get_vblank_timestamp() hook.
>
> Unfortunately, the FLIP_COMPLETE event depends on that timestamp,
> and the only way to regenerate a valid one is to have vblank
> interrupts enabled and have a valid in-ISR call to
> drm_crtc_handle_vblank.
>
> Additionally, if the user doesn't request vblanks but _does_ request
> FLIP_COMPLETE events, we still don't have a good timestamp: it'll be the
> same stamp as the last vblank one.
>
> Work around the issue by always enabling vblanks when the CRTC is on.
> Reducing the amount of time that PL0 has to be unmasked would be nice to
> fix at a later time.
>
> Changes since v1 [https://patchwork.freedesktop.org/patch/331727/]:
> - moved drm_crtc_vblank_put call to the ->atomic_disable() hook
>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: Liviu Dudau <Liviu.Dudau@arm.com>
> Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
> Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Pushed to drm-misc-next f59769c52cd7d158df53487ec2936f5592073340
Thanks,
Ayan
> ---
> drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> index 9ca5dbfd0723..75263d8cd0bd 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> @@ -249,6 +249,7 @@ komeda_crtc_atomic_enable(struct drm_crtc *crtc,
> {
> komeda_crtc_prepare(to_kcrtc(crtc));
> drm_crtc_vblank_on(crtc);
> + WARN_ON(drm_crtc_vblank_get(crtc));
> komeda_crtc_do_flush(crtc, old);
> }
>
> @@ -341,6 +342,7 @@ komeda_crtc_atomic_disable(struct drm_crtc *crtc,
> komeda_crtc_flush_and_wait_for_flip_done(kcrtc, disable_done);
> }
>
> + drm_crtc_vblank_put(crtc);
> drm_crtc_vblank_off(crtc);
> komeda_crtc_unprepare(kcrtc);
> }
> --
> 2.23.0
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 11+ messages in thread