Re: [PATCH] drm/msm/dsi: fix initialization in the bonded DSI case

[Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>]

On 11/25/2021 10:01 AM, Dmitry Baryshkov wrote:
> Commit 739b4e7756d3 ("drm/msm/dsi: Fix an error code in
> msm_dsi_modeset_init()") changed msm_dsi_modeset_init() to return an
> error code in case msm_dsi_manager_validate_current_config() returns
> false. However this is not an error case, but a slave DSI of the bonded
> DSI link. In this case msm_dsi_modeset_init() should return 0, but just
> skip connector and bridge initialization.
>
> To reduce possible confusion, drop the
> msm_dsi_manager_validate_current_config() function, and specif 'bonded
> && !master' condition directly in the msm_dsi_modeset_init().
>
> Fixes: 739b4e7756d3 ("drm/msm/dsi: Fix an error code in msm_dsi_modeset_init()")
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Reviewed-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> ---
>   drivers/gpu/drm/msm/dsi/dsi.c         | 10 +++++++---
>   drivers/gpu/drm/msm/dsi/dsi.h         |  1 -
>   drivers/gpu/drm/msm/dsi/dsi_manager.c | 17 -----------------
>   3 files changed, 7 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dsi/dsi.c b/drivers/gpu/drm/msm/dsi/dsi.c
> index 75ae3008b68f..fc280cc43494 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi.c
> @@ -215,9 +215,13 @@ int msm_dsi_modeset_init(struct msm_dsi *msm_dsi, struct drm_device *dev,
>   		goto fail;
>   	}
>   
> -	if (!msm_dsi_manager_validate_current_config(msm_dsi->id)) {
> -		ret = -EINVAL;
> -		goto fail;
> +	if (msm_dsi_is_bonded_dsi(msm_dsi) &&
> +	    !msm_dsi_is_master_dsi(msm_dsi)) {
> +		/*
> +		 * Do not return an eror here,
> +		 * Just skip creating encoder/connector for the slave-DSI.
> +		 */
> +		return 0;
>   	}
>   
>   	msm_dsi->encoder = encoder;
> diff --git a/drivers/gpu/drm/msm/dsi/dsi.h b/drivers/gpu/drm/msm/dsi/dsi.h
> index 66443dc98500..ef8212990254 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi.h
> +++ b/drivers/gpu/drm/msm/dsi/dsi.h
> @@ -82,7 +82,6 @@ int msm_dsi_manager_cmd_xfer(int id, const struct mipi_dsi_msg *msg);
>   bool msm_dsi_manager_cmd_xfer_trigger(int id, u32 dma_base, u32 len);
>   int msm_dsi_manager_register(struct msm_dsi *msm_dsi);
>   void msm_dsi_manager_unregister(struct msm_dsi *msm_dsi);
> -bool msm_dsi_manager_validate_current_config(u8 id);
>   void msm_dsi_manager_tpg_enable(void);
>   
>   /* msm dsi */
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> index a152dbf63038..a73cfeb93e90 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> @@ -645,23 +645,6 @@ struct drm_connector *msm_dsi_manager_connector_init(u8 id)
>   	return ERR_PTR(ret);
>   }
>   
> -bool msm_dsi_manager_validate_current_config(u8 id)
> -{
> -	bool is_bonded_dsi = IS_BONDED_DSI();
> -
> -	/*
> -	 * For bonded DSI, we only have one drm panel. For this
> -	 * use case, we register only one bridge/connector.
> -	 * Skip bridge/connector initialisation if it is
> -	 * slave-DSI for bonded DSI configuration.
> -	 */
> -	if (is_bonded_dsi && !IS_MASTER_DSI_LINK(id)) {
> -		DBG("Skip bridge registration for slave DSI->id: %d\n", id);
> -		return false;
> -	}
> -	return true;
> -}
> -
>   /* initialize bridge */
>   struct drm_bridge *msm_dsi_manager_bridge_init(u8 id)
>   {