Re: [PATCH 1/2] drm/dumb-buffers: reference the ioctl interface for its constraints

[Thomas Zimmermann]

Hi

Am 26.02.26 um 07:37 schrieb Icenowy Zheng:
> The current design of the DRM_IOCTL_MODE_CREATE_DUMB interface can only
> promise linear RGB buffers to be properly working.
>
> Add a reference to the interface from the document snippet for dumb
> objects (which is included by drm-kms.rst document and will end up in
> the built kernel documentation).
>
> Signed-off-by: Icenowy Zheng <zhengxingda@xxxxxxxxxxx>

Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx>

with a comment on wording below

> ---
>   drivers/gpu/drm/drm_dumb_buffers.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_dumb_buffers.c b/drivers/gpu/drm/drm_dumb_buffers.c
> index e2b62e5fb891b..5d535b230aad3 100644
> --- a/drivers/gpu/drm/drm_dumb_buffers.c
> +++ b/drivers/gpu/drm/drm_dumb_buffers.c
> @@ -57,7 +57,10 @@
>    *
>    * Note that dumb objects may not be used for gpu acceleration, as has been
>    * attempted on some ARM embedded platforms. Such drivers really must have
> - * a hardware-specific ioctl to allocate suitable buffer objects.
> + * a hardware-specific ioctl to allocate suitable buffer objects. The current
> + * userspace API also includes some constraints on the format and modifier to

Rather 'on the pixel format and framebuffer layout'.  The term modifier 
seems out of place here.

Best regards
Thomas

> + * be used with buffers backed by dumb objects, see &struct
> + * drm_mode_create_dumb for more details.
>    */
>   
>   static int drm_mode_align_dumb(struct drm_mode_create_dumb *args,

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)