[PATCH 17/20] drm: remove checks for same value in set_prop

[Chris Wilson]

On Wed,  1 Feb 2012 11:38:35 +0100, Sascha Hauer <s.hauer at pengutronix.de> wrote:
> The drivers currently check in set_property whether the property is
> unchanged. move this check into the core and do not bother the drivers
> with checking for unchanged properties.

This patch seems to have functional side-effects beyond the description.

For example,
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index db3b461..0024b59 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -2223,9 +2223,6 @@ intel_dp_set_property(struct drm_connector *connector,
>  		int i = val;
>  		bool has_audio;
>  
> -		if (i == intel_dp->force_audio)
> -			return 0;
> -

Here we are checking against the current value of the intel_dp, which
may in theory be modified elsewhere as well, and avoiding the modeswitch
if it is unnecessary. 
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre