[PATCH] qxl: fix framebuffer unpinning

[Gabriel Krisman Bertazi]

Gerd Hoffmann <kraxel at redhat.com> writes:

> qxl_plane_cleanup_fb() unpins the just activated framebuffer
> instead of the old one.  Oops.  Fix it.
>
> Cc: Gabriel Krisman Bertazi <krisman at collabora.co.uk>
> Fixes: 1277eed5fecb8830c8cc414ad70c1ef640464bc0
> Signed-off-by: Gerd Hoffmann <kraxel at redhat.com>
> ---
>  drivers/gpu/drm/qxl/qxl_display.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/qxl/qxl_display.c b/drivers/gpu/drm/qxl/qxl_display.c
> index e1dd05423e..afbf50d0c0 100644
> --- a/drivers/gpu/drm/qxl/qxl_display.c
> +++ b/drivers/gpu/drm/qxl/qxl_display.c
> @@ -702,14 +702,15 @@ static void qxl_plane_cleanup_fb(struct drm_plane *plane,
>  	struct drm_gem_object *obj;
>  	struct qxl_bo *user_bo;
>  
> -	if (!plane->state->fb) {
> -		/* we never executed prepare_fb, so there's nothing to
> +	if (!old_state->fb) {
> +		/*
> +		 * we never executed prepare_fb, so there's nothing to
>  		 * unpin.
>  		 */
>  		return;
>  	}
>  
> -	obj = to_qxl_framebuffer(plane->state->fb)->obj;
> +	obj = to_qxl_framebuffer(old_state->fb)->obj;

I am not sure about this patch.  My idea was to pin/unpin the current
buffer on prepare/cleanup, and only keep it pinned during the atomic
commit.  This was the goal of 37235451c6990683a8, for instance.

Anyway, if that goal is wrong, I think that, with your change, we forget to
unpin the final plane before removing the device.

Thanks,

-- 
Gabriel Krisman Bertazi