[Intel-gfx] [PATCH 01/20] drm: Let userspace check if driver supports modeset

[Souza, Jose]

Ping series review

On Wed, 2018-08-08 at 17:15 -0700, José Roberto de Souza wrote:
> GPU accelerators usually don't have display block or the display
> driver part can be disabled when building driver(for servers it saves
> some resources) so it is important let userspace check this
> capability too.
> 
> Right now we are checking
> drmModeGetResources()/drm_mode_getresources() for a error to detect
> if display is enabled but it is a hackish way as it can fail for
> other reasons too.
> 
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> ---
>  drivers/gpu/drm/drm_ioctl.c | 3 +++
>  include/uapi/drm/drm.h      | 1 +
>  2 files changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_ioctl.c
> b/drivers/gpu/drm/drm_ioctl.c
> index ea10e9a26aad..3a8438ae9b51 100644
> --- a/drivers/gpu/drm/drm_ioctl.c
> +++ b/drivers/gpu/drm/drm_ioctl.c
> @@ -244,6 +244,9 @@ static int drm_getcap(struct drm_device *dev,
> void *data, struct drm_file *file_
>  	case DRM_CAP_SYNCOBJ:
>  		req->value = drm_core_check_feature(dev,
> DRIVER_SYNCOBJ);
>  		return 0;
> +	case DRM_CAP_MODESET:
> +		req->value = drm_core_check_feature(dev,
> DRIVER_MODESET);
> +		return 0;
>  	}
>  
>  	/* Other caps only work with KMS drivers */
> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> index 300f336633f2..85fae6ddbf48 100644
> --- a/include/uapi/drm/drm.h
> +++ b/include/uapi/drm/drm.h
> @@ -649,6 +649,7 @@ struct drm_gem_open {
>  #define DRM_CAP_PAGE_FLIP_TARGET	0x11
>  #define DRM_CAP_CRTC_IN_VBLANK_EVENT	0x12
>  #define DRM_CAP_SYNCOBJ		0x13
> +#define DRM_CAP_MODESET		0x14
>  
>  /** DRM_IOCTL_GET_CAP ioctl argument type */
>  struct drm_get_cap {