[PATCH] drm: Simplify GETRESOURCES ioctl

[Chris Wilson]

On Sun, Dec 11, 2016 at 08:20:19PM +0100, Daniel Vetter wrote:
> Looping twice when we can do it once is silly. Also use a consistent
> style. Note that there's a good race with the connector list walking,
> since that is no longer protected by mode_config.mutex. But that's for
> a later patch to fix.
> 
> v2: Actually try to not blow up, somehow I lost the hunk that checks
> we don't copy too much. Noticed by Chris.
> 
> v3:
> - squash all drm_mode_getresources cleanups into one
> - use consistent style for walking objects (Chris)
> 
> v4:
> - Use u64_to_user_ptr (Chris)
> - Don't forget to copy the last connector (Chris)
> 
> v5: Chris was right ...
> 
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> ---
>  drivers/gpu/drm/drm_mode_config.c | 111 ++++++++++++++------------------------
>  1 file changed, 39 insertions(+), 72 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
> index 2735a5847ffa..b1e8bbceaf39 100644
> --- a/drivers/gpu/drm/drm_mode_config.c
> +++ b/drivers/gpu/drm/drm_mode_config.c
> @@ -84,17 +84,11 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
>  			  struct drm_file *file_priv)
>  {
>  	struct drm_mode_card_res *card_res = data;
> -	struct list_head *lh;
>  	struct drm_framebuffer *fb;
>  	struct drm_connector *connector;
>  	struct drm_crtc *crtc;
>  	struct drm_encoder *encoder;
> -	int ret = 0;
> -	int connector_count = 0;
> -	int crtc_count = 0;
> -	int fb_count = 0;
> -	int encoder_count = 0;
> -	int copied = 0;
> +	int count, ret = 0;

I'm down to a minor int but uABI uses u32. This being C, it all comes
out in the wash. One day we may have -Wsign-compare, but not today!

Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre