Re: [PATCH v2 22/23] drm/msm: Register the DCP backend

[Dmitry Baryshkov]

On Mon, Oct 26, 2026 at 11:51:32AM +0530, Jayant Shekhar wrote:
> The DCP platform driver provides an MSM KMS backend. Register it from the
> MSM DRM driver init and exit paths so the VirtIO driver can use the backend
> when the DCP function is discovered.
> 
> Add DCP registration hooks with no-op stubs when CONFIG_DRM_MSM_DCP is
> disabled. This keeps backend registration consistent with the other MSM
> display backends while allowing DCP support to remain optional.

There is no need to describe patch contents. Please update the prompts
you pass to your AI.

> 
> Assisted-by: LLM
> Signed-off-by: Jayant Shekhar <jayant.shekhar@xxxxxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/msm/msm_drv.c | 2 ++
>  drivers/gpu/drm/msm/msm_drv.h | 8 ++++++++
>  2 files changed, 10 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 5816c64d7ce7..d413c361c442 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -1208,6 +1208,7 @@ static int __init msm_drm_register(void)
>  	DBG("init");
>  	msm_mdp_register();
>  	msm_dpu_register();
> +	msm_dcp_register();
>  	msm_dsi_register();
>  	msm_hdmi_register();
>  	msm_dp_register();
> @@ -1229,6 +1230,7 @@ static void __exit msm_drm_unregister(void)
>  	msm_dsi_unregister();
>  	msm_mdp_unregister();
>  	msm_dpu_unregister();
> +	msm_dcp_unregister();
>  }
>  
>  module_init(msm_drm_register);
> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> index aa5dfd82ac6f..befaa9f2cb5c 100644
> --- a/drivers/gpu/drm/msm/msm_drv.h
> +++ b/drivers/gpu/drm/msm/msm_drv.h
> @@ -417,6 +417,14 @@ static inline void msm_dpu_register(void) {}
>  static inline void msm_dpu_unregister(void) {}
>  #endif
>  
> +#ifdef CONFIG_DRM_MSM_DCP
> +void msm_dcp_register(void);
> +void msm_dcp_unregister(void);

This means that the earlier patches generate "function without
prototype" warnings. Please fix that. The prototypes must come together
with the function definition.

> +#else
> +static inline void msm_dcp_register(void) {}
> +static inline void msm_dcp_unregister(void) {}
> +#endif
> +
>  #ifdef CONFIG_DRM_MSM_MDSS
>  void msm_mdss_register(void);
>  void msm_mdss_unregister(void);
> 
> -- 
> 2.43.0
> 

-- 
With best wishes
Dmitry