[PATCH 1/2] drm/msm/dpu: Add a function to retrieve the current CTL status

[PATCH 1/2] drm/msm/dpu: Add a function to retrieve the current CTL status

[AngeloGioacchino Del Regno]

Add a function that returns whether the requested CTL is active or not:
this will be used in a later commit to fix command mode panel issues.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c | 6 ++++++
 drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h | 7 +++++++
 2 files changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
index 64740ddb983e..3b6fd73eb3a8 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
@@ -91,6 +91,11 @@ static inline void dpu_hw_ctl_trigger_start(struct dpu_hw_ctl *ctx)
 	DPU_REG_WRITE(&ctx->hw, CTL_START, 0x1);
 }
 
+static inline bool dpu_hw_ctl_is_started(struct dpu_hw_ctl *ctx)
+{
+	return !!(DPU_REG_READ(&ctx->hw, CTL_START) & BIT(0));
+}
+
 static inline void dpu_hw_ctl_trigger_pending(struct dpu_hw_ctl *ctx)
 {
 	trace_dpu_hw_ctl_trigger_prepare(ctx->pending_flush_mask,
@@ -579,6 +584,7 @@ static void _setup_ctl_ops(struct dpu_hw_ctl_ops *ops,
 	ops->get_pending_flush = dpu_hw_ctl_get_pending_flush;
 	ops->get_flush_register = dpu_hw_ctl_get_flush_register;
 	ops->trigger_start = dpu_hw_ctl_trigger_start;
+	ops->is_started = dpu_hw_ctl_is_started;
 	ops->trigger_pending = dpu_hw_ctl_trigger_pending;
 	ops->reset = dpu_hw_ctl_reset_control;
 	ops->wait_reset_status = dpu_hw_ctl_wait_reset_status;
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
index 806c171e5df2..ac1544474022 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
@@ -61,6 +61,13 @@ struct dpu_hw_ctl_ops {
 	 */
 	void (*trigger_start)(struct dpu_hw_ctl *ctx);
 
+	/**
+	 * check if the ctl is started
+	 * @ctx       : ctl path ctx pointer
+	 * @Return: true if started, false if stopped
+	 */
+	bool (*is_started)(struct dpu_hw_ctl *ctx);
+
 	/**
 	 * kickoff prepare is in progress hw operation for sw
 	 * controlled interfaces: DSI cmd mode and WB interface
-- 
2.32.0

[PATCH 2/2] drm/msm/dpu: Fix timeout issues on command mode panels

[AngeloGioacchino Del Regno]

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 <angelogioacchino.delregno@somainline.org>
---
 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

Re: [PATCH 2/2] drm/msm/dpu: Fix timeout issues on command mode panels

[Marijn Suijten]

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 <angelogioacchino.delregno@somainline.org>
> ---
>  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/bdc67afc-3736-5497-c43f-5165c55e0354@somainline.org/

Thanks!

- Marijn

> +
>  	return _dpu_encoder_phys_cmd_wait_for_ctl_start(phys_enc);
>  }
>  
> -- 
> 2.32.0
> 

Re: [PATCH 2/2] drm/msm/dpu: Fix timeout issues on command mode panels

[AngeloGioacchino Del Regno]

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 <angelogioacchino.delregno@somainline.org>
>> ---
>>   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/bdc67afc-3736-5497-c43f-5165c55e0354@somainline.org/
> 
> 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
>>