[PATCH v4] drm/msm/dp: make eDP panel as the first connected connector

[PATCH v4] drm/msm/dp: make eDP panel as the first connected connector

[Kuogee Hsieh]

Some userspace presumes that the first connected connector is the main
display, where it's supposed to display e.g. the login screen. For
laptops, this should be the main panel.

This patch call drm_helper_move_panel_connectors_to_head() after
drm_bridge_connector_init() to make sure eDP stay at head of
connected connector list. This fixes unexpected corruption happen
at eDP panel if eDP is not placed at head of connected connector
list.

Changes in v2:
-- move drm_helper_move_panel_connectors_to_head() to
		dpu_kms_drm_obj_init()

Changes in v4:
-- move drm_helper_move_panel_connectors_to_head() to msm_drm_init()

Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
---
 drivers/gpu/drm/msm/msm_drv.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 4a3dda2..4d518c2 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -419,6 +419,8 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
 		}
 	}
 
+	drm_helper_move_panel_connectors_to_head(ddev);
+
 	ddev->mode_config.funcs = &mode_config_funcs;
 	ddev->mode_config.helper_private = &mode_config_helper_funcs;
 
-- 
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a Linux Foundation Collaborative Project

Re: [PATCH v4] drm/msm/dp: make eDP panel as the first connected connector

[Abhinav Kumar]

On 7/6/2022 12:32 PM, Kuogee Hsieh wrote:
> Some userspace presumes that the first connected connector is the main
> display, where it's supposed to display e.g. the login screen. For
> laptops, this should be the main panel.
> 
> This patch call drm_helper_move_panel_connectors_to_head() after
> drm_bridge_connector_init() to make sure eDP stay at head of
> connected connector list. This fixes unexpected corruption happen
> at eDP panel if eDP is not placed at head of connected connector
> list.
> 
> Changes in v2:
> -- move drm_helper_move_panel_connectors_to_head() to
> 		dpu_kms_drm_obj_init()
> 
> Changes in v4:
> -- move drm_helper_move_panel_connectors_to_head() to msm_drm_init()
> 
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
> ---
>   drivers/gpu/drm/msm/msm_drv.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 4a3dda2..4d518c2 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -419,6 +419,8 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
>   		}
>   	}
>   
> +	drm_helper_move_panel_connectors_to_head(ddev);
> +
>   	ddev->mode_config.funcs = &mode_config_funcs;
>   	ddev->mode_config.helper_private = &mode_config_helper_funcs;
>   

Re: [PATCH v4] drm/msm/dp: make eDP panel as the first connected connector

[Doug Anderson]

Hi,

On Wed, Jul 6, 2022 at 12:32 PM Kuogee Hsieh <quic_khsieh@quicinc.com> wrote:
>
> Some userspace presumes that the first connected connector is the main
> display, where it's supposed to display e.g. the login screen. For
> laptops, this should be the main panel.
>
> This patch call drm_helper_move_panel_connectors_to_head() after
> drm_bridge_connector_init() to make sure eDP stay at head of
> connected connector list. This fixes unexpected corruption happen
> at eDP panel if eDP is not placed at head of connected connector
> list.
>
> Changes in v2:
> -- move drm_helper_move_panel_connectors_to_head() to
>                 dpu_kms_drm_obj_init()
>
> Changes in v4:
> -- move drm_helper_move_panel_connectors_to_head() to msm_drm_init()
>
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
> ---
>  drivers/gpu/drm/msm/msm_drv.c | 2 ++
>  1 file changed, 2 insertions(+)

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>

NOTE: I tested this upstream with these two trees merged together:

msm-next: 1ff1da40d6fc Merge branches 'msm-next-lumag-core'...
qcom/for-next: d014f9463260 Merge branches 'arm64-for-5.20'...

...plus a revert to make things boot again [1]. I booted this on a
sc7280-herobrine running Chrome OS. When I do this, the original
reported glitching is fixed (yay) and I think we should land it.

...but I'm not convinced that all glitching is fixed by this. In
particular I've occasionally seen an underrun at bootup (blue color)
followed by a temporary glitch. With the above plus ${SUBJECT} patch I
also reliably see a glitch on my external (DP) display every time I
plug in. I don't see either on the downstream Chrome OS kernel,
though...

[1] https://lore.kernel.org/r/20220706144706.1.I48f35820bf3670d54940110462555c2d0a6d5eb2@changeid

Re: [PATCH v4] drm/msm/dp: make eDP panel as the first connected connector

[Dmitry Baryshkov]

On 06/07/2022 22:32, Kuogee Hsieh wrote:
> Some userspace presumes that the first connected connector is the main
> display, where it's supposed to display e.g. the login screen. For
> laptops, this should be the main panel.
> 
> This patch call drm_helper_move_panel_connectors_to_head() after
> drm_bridge_connector_init() to make sure eDP stay at head of
> connected connector list. This fixes unexpected corruption happen
> at eDP panel if eDP is not placed at head of connected connector
> list.
> 
> Changes in v2:
> -- move drm_helper_move_panel_connectors_to_head() to
> 		dpu_kms_drm_obj_init()
> 
> Changes in v4:
> -- move drm_helper_move_panel_connectors_to_head() to msm_drm_init()
> 
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

> ---
>   drivers/gpu/drm/msm/msm_drv.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 4a3dda2..4d518c2 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -419,6 +419,8 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
>   		}
>   	}
>   
> +	drm_helper_move_panel_connectors_to_head(ddev);
> +
>   	ddev->mode_config.funcs = &mode_config_funcs;
>   	ddev->mode_config.helper_private = &mode_config_helper_funcs;
>   


-- 
With best wishes
Dmitry

Re: [PATCH v4] drm/msm/dp: make eDP panel as the first connected connector

[Stephen Boyd]

Quoting Kuogee Hsieh (2022-07-06 12:32:08)
> Some userspace presumes that the first connected connector is the main
> display, where it's supposed to display e.g. the login screen. For
> laptops, this should be the main panel.
>
> This patch call drm_helper_move_panel_connectors_to_head() after
> drm_bridge_connector_init() to make sure eDP stay at head of
> connected connector list. This fixes unexpected corruption happen
> at eDP panel if eDP is not placed at head of connected connector
> list.
>
> Changes in v2:
> -- move drm_helper_move_panel_connectors_to_head() to
>                 dpu_kms_drm_obj_init()
>
> Changes in v4:
> -- move drm_helper_move_panel_connectors_to_head() to msm_drm_init()
>
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
> ---

Reviewed-by: Stephen Boyd <swboyd@chromium.org>

Re: [PATCH v4] drm/msm/dp: make eDP panel as the first connected connector

[Abhinav Kumar]

On 7/6/2022 12:32 PM, Kuogee Hsieh wrote:
> Some userspace presumes that the first connected connector is the main
> display, where it's supposed to display e.g. the login screen. For
> laptops, this should be the main panel.
> 
> This patch call drm_helper_move_panel_connectors_to_head() after
> drm_bridge_connector_init() to make sure eDP stay at head of
> connected connector list. This fixes unexpected corruption happen
> at eDP panel if eDP is not placed at head of connected connector
> list.
> 
> Changes in v2:
> -- move drm_helper_move_panel_connectors_to_head() to
> 		dpu_kms_drm_obj_init()
> 
> Changes in v4:
> -- move drm_helper_move_panel_connectors_to_head() to msm_drm_init()
> 
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Fixes: c8afe684c95c ("drm/msm: basic KMS driver for snapdragon")
> ---
>   drivers/gpu/drm/msm/msm_drv.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 4a3dda2..4d518c2 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -419,6 +419,8 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
>   		}
>   	}
>   
> +	drm_helper_move_panel_connectors_to_head(ddev);
> +
>   	ddev->mode_config.funcs = &mode_config_funcs;
>   	ddev->mode_config.helper_private = &mode_config_helper_funcs;
>   

Re: [PATCH v4] drm/msm/dp: make eDP panel as the first connected connector

[Abhinav Kumar]

On 7/20/2022 11:47 AM, Abhinav Kumar wrote:
> 
> 
> On 7/6/2022 12:32 PM, Kuogee Hsieh wrote:
>> Some userspace presumes that the first connected connector is the main
>> display, where it's supposed to display e.g. the login screen. For
>> laptops, this should be the main panel.
>>
>> This patch call drm_helper_move_panel_connectors_to_head() after
>> drm_bridge_connector_init() to make sure eDP stay at head of
>> connected connector list. This fixes unexpected corruption happen
>> at eDP panel if eDP is not placed at head of connected connector
>> list.
>>
>> Changes in v2:
>> -- move drm_helper_move_panel_connectors_to_head() to
>>         dpu_kms_drm_obj_init()
>>
>> Changes in v4:
>> -- move drm_helper_move_panel_connectors_to_head() to msm_drm_init()
>>
>> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
> Fixes: c8afe684c95c ("drm/msm: basic KMS driver for snapdragon")

Lets drop the previous fixes tag and use this one as its more recent and 
appropriate as it added eDP support for sc7280.

Fixes: ef7837ff091c ("drm/msm/dp: Add DP controllers for sc7280")

>> ---
>>   drivers/gpu/drm/msm/msm_drv.c | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/msm/msm_drv.c 
>> b/drivers/gpu/drm/msm/msm_drv.c
>> index 4a3dda2..4d518c2 100644
>> --- a/drivers/gpu/drm/msm/msm_drv.c
>> +++ b/drivers/gpu/drm/msm/msm_drv.c
>> @@ -419,6 +419,8 @@ static int msm_drm_init(struct device *dev, const 
>> struct drm_driver *drv)
>>           }
>>       }
>> +    drm_helper_move_panel_connectors_to_head(ddev);
>> +
>>       ddev->mode_config.funcs = &mode_config_funcs;
>>       ddev->mode_config.helper_private = &mode_config_helper_funcs;