Re: [PATCH 5/7] drm/xe/display: Add macro with display driver features

[Jani Nikula <jani.nikula@intel.com>]

On Tue, 12 May 2026, Michal Wajdeczko <michal.wajdeczko@intel.com> wrote:
> Instead of updating drm_driver.driver_features in the runtime, we
> can use macro which value depends on the CONFIG_DRM_XE_DISPLAY.
>
> And if display support is later disabled by the xe_modparam then we
> will clear related bits in the drm_device.driver_features instead.
>
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
> Cc: Jani Nikula <jani.nikula@intel.com>
> ---
>  drivers/gpu/drm/xe/display/xe_display.c | 4 +---
>  drivers/gpu/drm/xe/display/xe_display.h | 2 ++
>  drivers/gpu/drm/xe/xe_device.c          | 2 ++
>  3 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/display/xe_display.c b/drivers/gpu/drm/xe/display/xe_display.c
> index 7e7d476da8ce..7e5382fc161d 100644
> --- a/drivers/gpu/drm/xe/display/xe_display.c
> +++ b/drivers/gpu/drm/xe/display/xe_display.c
> @@ -84,13 +84,11 @@ void xe_display_driver_set_hooks(struct drm_driver *driver)
>  {
>  	if (!xe_modparam.probe_display)
>  		return;
> -
> -	driver->driver_features |= DRIVER_MODESET | DRIVER_ATOMIC;

This is also bonkers, because it modifies the driver for *all* devices.

I think the patch subject downplays the actual change, but *shrug*.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

>  }
>  
>  static void unset_display_features(struct xe_device *xe)
>  {
> -	xe->drm.driver_features &= ~(DRIVER_MODESET | DRIVER_ATOMIC);
> +	xe->drm.driver_features &= ~XE_DISPLAY_DRIVER_FEATURES;
>  }
>  
>  static void xe_display_fini_early(void *arg)
> diff --git a/drivers/gpu/drm/xe/display/xe_display.h b/drivers/gpu/drm/xe/display/xe_display.h
> index deec0232532e..d2b105d5f2a1 100644
> --- a/drivers/gpu/drm/xe/display/xe_display.h
> +++ b/drivers/gpu/drm/xe/display/xe_display.h
> @@ -44,12 +44,14 @@ void xe_display_pm_runtime_suspend(struct xe_device *xe);
>  void xe_display_pm_runtime_suspend_late(struct xe_device *xe);
>  void xe_display_pm_runtime_resume(struct xe_device *xe);
>  
> +#define XE_DISPLAY_DRIVER_FEATURES	(DRIVER_MODESET | DRIVER_ATOMIC)
>  #define XE_DISPLAY_DRIVER_OPS						\
>  	.fbdev_probe = PTR_IF(IS_ENABLED(CONFIG_DRM_FBDEV_EMULATION),	\
>  			      xe_display_driver_fbdev_probe)
>  
>  #else
>  
> +#define XE_DISPLAY_DRIVER_FEATURES	0
>  #define XE_DISPLAY_DRIVER_OPS \
>  	.fbdev_probe = NULL
>  
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 3bca4c1d1d5f..c053e4d2692f 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -393,6 +393,7 @@ bool xe_is_xe_file(const struct file *file)
>  
>  static struct drm_driver regular_driver = {
>  	.driver_features =
> +	    XE_DISPLAY_DRIVER_FEATURES |
>  	    DRIVER_GEM |
>  	    DRIVER_RENDER | DRIVER_SYNCOBJ |
>  	    DRIVER_SYNCOBJ_TIMELINE | DRIVER_GEM_GPUVA,
> @@ -425,6 +426,7 @@ static const struct drm_ioctl_desc xe_ioctls_admin_only[] = {
>  
>  static struct drm_driver admin_only_driver = {
>  	.driver_features =
> +	    XE_DISPLAY_DRIVER_FEATURES |
>  	    DRIVER_GEM | DRIVER_RENDER | DRIVER_GEM_GPUVA,
>  	.open = xe_file_open,
>  	.postclose = xe_file_close,

-- 
Jani Nikula, Intel