Re: [PATCH] drm/amd/display: add stub for crtc_debugfs_init()

[Harry Wentland <harry.wentland@amd.com>]

On 2022-06-14 11:57, Randy Dunlap wrote:
> Fix build error when CONFIG_DEBUG_FS is not enabled by adding a
> stub function for crtc_debugfs_init().
> 
> Eliminates this build error:
> 
> ../drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c: In function ‘amdgpu_dm_crtc_late_register’:
> ../drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:6599:2: error: implicit declaration of function ‘crtc_debugfs_init’; did you mean ‘amdgpu_debugfs_init’? [-Werror=implicit-function-declaration]
>   crtc_debugfs_init(crtc);
>   ^~~~~~~~~~~~~~~~~
>   amdgpu_debugfs_init
> 
> Fixes: 86bc22191892 ("drm/amd/display: Support crc on specific region")

That whole patch and the whole secure display feature depend on debugfs.
It should never try building without CONFIG_DEBUG_FS.

See drivers/gpu/drm/amd/display/Kconfig:

> config DRM_AMD_SECURE_DISPLAY
>         bool "Enable secure display support"
>         default n
>         depends on DEBUG_FS
>         depends on DRM_AMD_DC_DCN
>         help
>             Choose this option if you want to
>             support secure display
> 
>             This option enables the calculation
>             of crc of specific region via debugfs.
>             Cooperate with specific DMCU FW.

amdgpu_dm_crtc_late_register is guarded by CONIG_DRM_AMD_SECURE_DISPLAY.

Harry

> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> Cc: Wayne Lin <Wayne.Lin@amd.com>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: Christian König <christian.koenig@amd.com>
> Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
> Cc: amd-gfx@lists.freedesktop.org
> Cc: dri-devel@lists.freedesktop.org
> ---
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c         |    2 --
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.h |    6 ++++++
>  2 files changed, 6 insertions(+), 2 deletions(-)
> 
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -57,9 +57,7 @@
>  #include "amdgpu_dm_irq.h"
>  #include "dm_helpers.h"
>  #include "amdgpu_dm_mst_types.h"
> -#if defined(CONFIG_DEBUG_FS)
>  #include "amdgpu_dm_debugfs.h"
> -#endif
>  #include "amdgpu_dm_psr.h"
>  
>  #include "ivsrcid/ivsrcid_vislands30.h"
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.h
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.h
> @@ -31,6 +31,12 @@
>  
>  void connector_debugfs_init(struct amdgpu_dm_connector *connector);
>  void dtn_debugfs_init(struct amdgpu_device *adev);
> +
> +#ifdef CONFIG_DEBUG_FS
>  void crtc_debugfs_init(struct drm_crtc *crtc);
> +#else
> +static inline void crtc_debugfs_init(struct drm_crtc *crtc)
> +{}
> +#endif
>  
>  #endif