Re: [PATCH 2/2] drm: virtio: fix virtio_gpu_mode_dumb_create

[Daniel Vetter]

On Mon, Apr 03, 2017 at 09:08:45AM +0200, Gerd Hoffmann wrote:
> Lookup format using virtio_gpu_translate_format()
> instead of hardcoding it.  Fixes xorg display on
> bigendian guests (i.e. ppc64).
> 
> Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>

ow ... :(

With what kind of client have you tested this? fbdev? kms native?

Should we patch drm_fourcc.h and essentially state that _all_ drm_fourcc
are in native endian, don't dare mixing things up? Would be good to send
out an rfc and discuss it with radeon/amd maintainers. Afaik they are the
only ones who also care about some big endian platforms.

On the patch itself, once you've added more details about what/how it
falls over:

Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
-Daniel

> ---
>  drivers/gpu/drm/virtio/virtgpu_gem.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/virtio/virtgpu_gem.c b/drivers/gpu/drm/virtio/virtgpu_gem.c
> index 336a57f..cc025d8 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_gem.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_gem.c
> @@ -88,6 +88,7 @@ int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
>  	int ret;
>  	uint32_t pitch;
>  	uint32_t resid;
> +	uint32_t format;
>  
>  	pitch = args->width * ((args->bpp + 1) / 8);
>  	args->size = pitch * args->height;
> @@ -98,9 +99,10 @@ int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
>  	if (ret)
>  		goto fail;
>  
> +	format = virtio_gpu_translate_format(DRM_FORMAT_XRGB8888);
>  	virtio_gpu_resource_id_get(vgdev, &resid);
> -	virtio_gpu_cmd_create_resource(vgdev, resid,
> -				       2, args->width, args->height);
> +	virtio_gpu_cmd_create_resource(vgdev, resid, format,
> +				       args->width, args->height);
>  
>  	/* attach the object to the resource */
>  	obj = gem_to_virtio_gpu_obj(gobj);
> -- 
> 2.9.3
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch