Re: [PATCH v3 10/33] drm/vkms: Introduce configfs for plane rotation

Luca Ceresoli
2025-12-23T11:14:17Z

On Mon Dec 22, 2025 at 11:11 AM CET, Louis Chauvet wrote:
> To allows the userspace to test many hardware configurations, introduce a
> new interface to configure the available rotation per planes. VKMS
> supports any rotation and reflection, so the userspace can choose any
> combination.
>
> The supported rotations are configured by writing a rotation bitmask to
> the file `supported_rotations` and the default rotation is chosen by
> writing a rotation bitmask to `default_rotation`.
>
> Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>

> --- a/drivers/gpu/drm/vkms/vkms_configfs.c
> +++ b/drivers/gpu/drm/vkms/vkms_configfs.c
> @@ -365,24 +365,105 @@ static ssize_t plane_name_store(struct config_item *item, const char *page,
> return (ssize_t)count;
> }
>
> +static ssize_t plane_supported_rotations_show(struct config_item *item, char *page)
> +{
> + struct vkms_configfs_plane *plane;
> + unsigned int plane_supported_rotations;
> +
> + plane = plane_item_to_vkms_configfs_plane(item);

You seem to have missed "assign on declaration" here (but you did it in
plane_default_rotation_show()).

The code added w.r.t. v2 looks OK as well, so with the above nit fixed:

Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering