In function dpu_encoder_phys_cmd_wait_for_commit_done we are always
checking if the relative CTL is started by waiting for an interrupt
to fire: it is fine to do that, but then sometimes we call this
function while the CTL is up and has never been put down, but that
interrupt gets raised only when the CTL gets a state change from
0 to 1 (disabled to enabled), so we're going to wait for something
that will never happen on its own.
Solving this while avoiding to restart the CTL is actually possible
and can be done by just checking if it is already up and running
when the wait_for_commit_done function is called: in this case, so,
if the CTL was already running, we can say that the commit is done
if the command transmission is complete (in other terms, if the
interface has been flushed).
Signed-off-by: AngeloGioacchino Del Regno <[email protected]>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
index aa01698d6b25..b5b1b555ac4e 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
@@ -682,6 +682,9 @@ static int dpu_encoder_phys_cmd_wait_for_commit_done(
if (!dpu_encoder_phys_cmd_is_master(phys_enc))
return 0;
+ if (phys_enc->hw_ctl->ops.is_started)
+ return dpu_encoder_phys_cmd_wait_for_tx_complete(phys_enc);
+
return _dpu_encoder_phys_cmd_wait_for_ctl_start(phys_enc);
}
--
2.32.0
Hi Angelo!
On 2021-09-01 19:43:47, AngeloGioacchino Del Regno wrote:
> In function dpu_encoder_phys_cmd_wait_for_commit_done we are always
> checking if the relative CTL is started by waiting for an interrupt
> to fire: it is fine to do that, but then sometimes we call this
> function while the CTL is up and has never been put down, but that
> interrupt gets raised only when the CTL gets a state change from
> 0 to 1 (disabled to enabled), so we're going to wait for something
> that will never happen on its own.
>
> Solving this while avoiding to restart the CTL is actually possible
> and can be done by just checking if it is already up and running
> when the wait_for_commit_done function is called: in this case, so,
> if the CTL was already running, we can say that the commit is done
> if the command transmission is complete (in other terms, if the
> interface has been flushed).
>
> Signed-off-by: AngeloGioacchino Del Regno <[email protected]>
> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> index aa01698d6b25..b5b1b555ac4e 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> @@ -682,6 +682,9 @@ static int dpu_encoder_phys_cmd_wait_for_commit_done(
> if (!dpu_encoder_phys_cmd_is_master(phys_enc))
> return 0;
>
> + if (phys_enc->hw_ctl->ops.is_started)
> + return dpu_encoder_phys_cmd_wait_for_tx_complete(phys_enc);
In the previous commit you introduced is_started to the ops struct as
function pointer, and you probably intend to call it here instead of
just checking whether it might be NULL.
As far as I remember this was also the reason for previously mentioning
that it was faulty and required a v2 in:
https://lore.kernel.org/linux-arm-msm/[email protected]/
Thanks!
- Marijn
> +
> return _dpu_encoder_phys_cmd_wait_for_ctl_start(phys_enc);
> }
>
> --
> 2.32.0
>
Il 10/09/21 23:48, Marijn Suijten ha scritto:
> Hi Angelo!
>
> On 2021-09-01 19:43:47, AngeloGioacchino Del Regno wrote:
>> In function dpu_encoder_phys_cmd_wait_for_commit_done we are always
>> checking if the relative CTL is started by waiting for an interrupt
>> to fire: it is fine to do that, but then sometimes we call this
>> function while the CTL is up and has never been put down, but that
>> interrupt gets raised only when the CTL gets a state change from
>> 0 to 1 (disabled to enabled), so we're going to wait for something
>> that will never happen on its own.
>>
>> Solving this while avoiding to restart the CTL is actually possible
>> and can be done by just checking if it is already up and running
>> when the wait_for_commit_done function is called: in this case, so,
>> if the CTL was already running, we can say that the commit is done
>> if the command transmission is complete (in other terms, if the
>> interface has been flushed).
>>
>> Signed-off-by: AngeloGioacchino Del Regno <[email protected]>
>> ---
>> drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
>> index aa01698d6b25..b5b1b555ac4e 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
>> @@ -682,6 +682,9 @@ static int dpu_encoder_phys_cmd_wait_for_commit_done(
>> if (!dpu_encoder_phys_cmd_is_master(phys_enc))
>> return 0;
>>
>> + if (phys_enc->hw_ctl->ops.is_started)
>> + return dpu_encoder_phys_cmd_wait_for_tx_complete(phys_enc);
>
> In the previous commit you introduced is_started to the ops struct as
> function pointer, and you probably intend to call it here instead of
> just checking whether it might be NULL.
>
> As far as I remember this was also the reason for previously mentioning
> that it was faulty and required a v2 in:
> https://lore.kernel.org/linux-arm-msm/[email protected]/
>
> Thanks!
>
> - Marijn
>
Ugh. I've pulled this from the wrong tree.
Sending a v2 asap.
>> +
>> return _dpu_encoder_phys_cmd_wait_for_ctl_start(phys_enc);
>> }
>>
>> --
>> 2.32.0
>>