linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] drm/msm/dp: update is_connected status base on sink count at dp_pm_resume()
@ 2021-07-28 21:30 Kuogee Hsieh
  2021-07-30 18:57 ` Stephen Boyd
  0 siblings, 1 reply; 3+ messages in thread
From: Kuogee Hsieh @ 2021-07-28 21:30 UTC (permalink / raw)
  To: robdclark, sean, swboyd, vkoul, agross, bjorn.andersson
  Cc: abhinavk, aravindh, khsieh, freedreno, dri-devel, linux-arm-msm,
	linux-kernel

Currently at dp_pm_resume() is_connected state is decided base on hpd connection
status only. This will put is_connected in wrongly "true" state at the scenario
that dongle attached to DUT but without hmdi cable connecting to it. Fix this
problem by adding read sink count from dongle and decided is_connected state base
on both sink count and hpd connection status.

Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
---
 drivers/gpu/drm/msm/dp/dp_display.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 2b660e9..9bcb261 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -1308,6 +1308,17 @@ static int dp_display_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static int dp_get_sink_count(struct dp_display_private *dp)
+{
+	u8 sink_count;
+
+	sink_count = drm_dp_read_sink_count(dp->aux);
+	if (sink_count < 0)
+		return 0;
+
+	return sink_count;
+}
+
 static int dp_pm_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
@@ -1327,14 +1338,22 @@ static int dp_pm_resume(struct device *dev)
 
 	dp_catalog_ctrl_hpd_config(dp->catalog);
 
-	status = dp_catalog_link_is_connected(dp->catalog);
+	/*
+	 * set sink to normal operation mode -- D0
+	 * before dpcd read
+	 */
+	dp_link_psm_config(dp->link, &dp->panel->link_info, false);
 
+	if ((status = dp_catalog_link_is_connected(dp->catalog)))
+		dp->link->sink_count = dp_get_sink_count(dp);
+	else
+		dp->link->sink_count = 0;
 	/*
 	 * can not declared display is connected unless
 	 * HDMI cable is plugged in and sink_count of
 	 * dongle become 1
 	 */
-	if (status && dp->link->sink_count)
+	if (dp->link->sink_count)
 		dp->dp_display.is_connected = true;
 	else
 		dp->dp_display.is_connected = false;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] drm/msm/dp: update is_connected status base on sink count at dp_pm_resume()
  2021-07-28 21:30 [PATCH] drm/msm/dp: update is_connected status base on sink count at dp_pm_resume() Kuogee Hsieh
@ 2021-07-30 18:57 ` Stephen Boyd
  2021-08-02 16:10   ` khsieh
  0 siblings, 1 reply; 3+ messages in thread
From: Stephen Boyd @ 2021-07-30 18:57 UTC (permalink / raw)
  To: Kuogee Hsieh, agross, bjorn.andersson, robdclark, sean, vkoul
  Cc: abhinavk, aravindh, freedreno, dri-devel, linux-arm-msm, linux-kernel

Quoting Kuogee Hsieh (2021-07-28 14:30:54)
> Currently at dp_pm_resume() is_connected state is decided base on hpd connection
> status only. This will put is_connected in wrongly "true" state at the scenario
> that dongle attached to DUT but without hmdi cable connecting to it. Fix this
> problem by adding read sink count from dongle and decided is_connected state base
> on both sink count and hpd connection status.
>

Please add a Fixes tag.

> Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
> ---
>  drivers/gpu/drm/msm/dp/dp_display.c | 23 +++++++++++++++++++++--
>  1 file changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index 2b660e9..9bcb261 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -1308,6 +1308,17 @@ static int dp_display_remove(struct platform_device *pdev)
>         return 0;
>  }
>
> +static int dp_get_sink_count(struct dp_display_private *dp)
> +{
> +       u8 sink_count;
> +
> +       sink_count = drm_dp_read_sink_count(dp->aux);

drm_dp_read_sink_count() returns an int, not a u8. Comparing a u8 to
less than zero doesn't make any sense as it isn't signed.

> +       if (sink_count < 0)
> +               return 0;
> +
> +       return sink_count;
> +}

We can drop this function and just have an int count in dp_pm_resume()
that is compared to < 0 and then ignored.

> +
>  static int dp_pm_resume(struct device *dev)
>  {
>         struct platform_device *pdev = to_platform_device(dev);
> @@ -1327,14 +1338,22 @@ static int dp_pm_resume(struct device *dev)
>
>         dp_catalog_ctrl_hpd_config(dp->catalog);
>
> -       status = dp_catalog_link_is_connected(dp->catalog);
> +       /*
> +        * set sink to normal operation mode -- D0
> +        * before dpcd read
> +        */
> +       dp_link_psm_config(dp->link, &dp->panel->link_info, false);
>
> +       if ((status = dp_catalog_link_is_connected(dp->catalog)))
> +               dp->link->sink_count = dp_get_sink_count(dp);

Do we need to call drm_dp_read_sink_count_cap() as well?

> +       else
> +               dp->link->sink_count = 0;
>         /*
>          * can not declared display is connected unless
>          * HDMI cable is plugged in and sink_count of
>          * dongle become 1
>          */
> -       if (status && dp->link->sink_count)

Is 'status' used anymore? If not, please remove it.

> +       if (dp->link->sink_count)
>                 dp->dp_display.is_connected = true;
>         else
>                 dp->dp_display.is_connected = false;

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] drm/msm/dp: update is_connected status base on sink count at dp_pm_resume()
  2021-07-30 18:57 ` Stephen Boyd
@ 2021-08-02 16:10   ` khsieh
  0 siblings, 0 replies; 3+ messages in thread
From: khsieh @ 2021-08-02 16:10 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: agross, bjorn.andersson, robdclark, sean, vkoul, abhinavk,
	aravindh, freedreno, dri-devel, linux-arm-msm, linux-kernel

On 2021-07-30 11:57, Stephen Boyd wrote:
> Quoting Kuogee Hsieh (2021-07-28 14:30:54)
>> Currently at dp_pm_resume() is_connected state is decided base on hpd 
>> connection
>> status only. This will put is_connected in wrongly "true" state at the 
>> scenario
>> that dongle attached to DUT but without hmdi cable connecting to it. 
>> Fix this
>> problem by adding read sink count from dongle and decided is_connected 
>> state base
>> on both sink count and hpd connection status.
>> 
> 
> Please add a Fixes tag.
> 
>> Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
>> ---
>>  drivers/gpu/drm/msm/dp/dp_display.c | 23 +++++++++++++++++++++--
>>  1 file changed, 21 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c 
>> b/drivers/gpu/drm/msm/dp/dp_display.c
>> index 2b660e9..9bcb261 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_display.c
>> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
>> @@ -1308,6 +1308,17 @@ static int dp_display_remove(struct 
>> platform_device *pdev)
>>         return 0;
>>  }
>> 
>> +static int dp_get_sink_count(struct dp_display_private *dp)
>> +{
>> +       u8 sink_count;
>> +
>> +       sink_count = drm_dp_read_sink_count(dp->aux);
> 
> drm_dp_read_sink_count() returns an int, not a u8. Comparing a u8 to
> less than zero doesn't make any sense as it isn't signed.
> 
>> +       if (sink_count < 0)
>> +               return 0;
>> +
>> +       return sink_count;
>> +}
> 
> We can drop this function and just have an int count in dp_pm_resume()
> that is compared to < 0 and then ignored.
> 
>> +
>>  static int dp_pm_resume(struct device *dev)
>>  {
>>         struct platform_device *pdev = to_platform_device(dev);
>> @@ -1327,14 +1338,22 @@ static int dp_pm_resume(struct device *dev)
>> 
>>         dp_catalog_ctrl_hpd_config(dp->catalog);
>> 
>> -       status = dp_catalog_link_is_connected(dp->catalog);
>> +       /*
>> +        * set sink to normal operation mode -- D0
>> +        * before dpcd read
>> +        */
>> +       dp_link_psm_config(dp->link, &dp->panel->link_info, false);
>> 
>> +       if ((status = dp_catalog_link_is_connected(dp->catalog)))
>> +               dp->link->sink_count = dp_get_sink_count(dp);
> 
> Do we need to call drm_dp_read_sink_count_cap() as well?
no, we only need sink_count
> 
>> +       else
>> +               dp->link->sink_count = 0;
>>         /*
>>          * can not declared display is connected unless
>>          * HDMI cable is plugged in and sink_count of
>>          * dongle become 1
>>          */
>> -       if (status && dp->link->sink_count)
> 
> Is 'status' used anymore? If not, please remove it.
Yes, it still used which used to decided to perform dpcd read sink count 
or not
> 
>> +       if (dp->link->sink_count)
>>                 dp->dp_display.is_connected = true;
>>         else
>>                 dp->dp_display.is_connected = false;

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-08-02 16:10 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-28 21:30 [PATCH] drm/msm/dp: update is_connected status base on sink count at dp_pm_resume() Kuogee Hsieh
2021-07-30 18:57 ` Stephen Boyd
2021-08-02 16:10   ` khsieh

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).