[Intel-gfx] [PATCH v5 2/3] drm/i915/gen9: Fix PCODE polling during CDCLK change notification

[Chris Wilson]

On Mon, Nov 28, 2016 at 06:40:33PM +0200, Imre Deak wrote:
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 66c62f3..4e06e92 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -7864,6 +7864,59 @@ int sandybridge_pcode_write(struct drm_i915_private *dev_priv,
>  	return 0;
>  }
>  
> +static bool skl_pcode_try_request(struct drm_i915_private *dev_priv, u32 mbox,
> +				  u32 request, u32 reply_mask, u32 reply,
> +				  u32 *status)
> +{
> +	u32 val = request;
> +
> +	*status = sandybridge_pcode_read(dev_priv, mbox, &val);

Hmm. This in turn uses a plain wait_for() that we want to stop relying
on drm_can_sleep() in future. Right now, it's ok but we're just making
things harder for ourselves later. I'm not keen on the alternative
though (passing around I am atomic flags, or making more things atomic
by default). :|
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre