[PATCH 1/2] drm/nouveau: Disable atomic support on a per-device basis

[Lyude Paul]

Hm, one nitpick here. Since /sys/kernel/debug/dri/*/state creation depends on
the driver supporting atomic, maybe it would be good to make it so that we set
DRIVER_ATOMIC in the driver_stub structure, then disable it per-device depending
on the nouveau_atomic setting + hw support. That way we can always have the
state debugfs file while maintaining nouveau's current behavior with exposing
atomic ioctls. Assuming that wouldn't have any unintended side-effects of course

On Thu, 2018-09-13 at 19:31 +0300, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> We now have per-device driver_features, so let's use that
> to disable atomic only for pre-nv50.
> 
> Cc: Ben Skeggs <bskeggs at redhat.com>
> Cc: Lyude Paul <lyude at redhat.com>
> Cc: nouveau at lists.freedesktop.org
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> Suggested-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/nouveau/dispnv04/disp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/dispnv04/disp.c
> b/drivers/gpu/drm/nouveau/dispnv04/disp.c
> index 70dce544984e..670535a68d3b 100644
> --- a/drivers/gpu/drm/nouveau/dispnv04/disp.c
> +++ b/drivers/gpu/drm/nouveau/dispnv04/disp.c
> @@ -56,7 +56,7 @@ nv04_display_create(struct drm_device *dev)
>  	nouveau_display(dev)->fini = nv04_display_fini;
>  
>  	/* Pre-nv50 doesn't support atomic, so don't expose the ioctls */
> -	dev->driver->driver_features &= ~DRIVER_ATOMIC;
> +	dev->driver_features &= ~DRIVER_ATOMIC;
>  
>  	nouveau_hw_save_vga_fonts(dev, 1);
>