[PATCH 2/3] drm/i915: WARN if RPS adjustment is more than range

[Chris Wilson]

On Fri, Jan 13, 2017 at 03:46:11PM +0530, Sagar Arun Kamble wrote:
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_irq.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index ce5663d..b85bef9 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -1195,6 +1195,8 @@ static void gen6_pm_rps_work(struct work_struct *work)
>  		adj = 0;
>  	}
>  
> +	WARN_ON(abs(adj) > (max-min));

Do we actually care? The adjustment is just an exponential function that
will be clamped (and then when it is finally clamped will become zero).
Before it is clamped, it is quite permissible that the last adj will be
larger than the entire range.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre