[Intel-gfx] [PATCH 4/5] drm/i915/guc: Increase wait timeout for doorbell release status update

[Michal Wajdeczko]

On Sun, 05 Nov 2017 14:39:42 +0100, Sagar Arun Kamble  
<sagar.a.kamble at intel.com> wrote:

> Current wait timeout of 10us is very tight as seen on SKL/KBL randomly
> for pm_rpm at basic-pci-d3-state. Increase it to 50us.
>
> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Michał Winiarski <michal.winiarski at intel.com>
> Cc: Michel Thierry <michel.thierry at intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Arkadiusz Hiler <arkadiusz.hiler at intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_guc_submission.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c  
> b/drivers/gpu/drm/i915/i915_guc_submission.c
> index 21f7fa7..3914415 100644
> --- a/drivers/gpu/drm/i915/i915_guc_submission.c
> +++ b/drivers/gpu/drm/i915/i915_guc_submission.c
> @@ -222,7 +222,8 @@ static int __destroy_doorbell(struct i915_guc_client  
> *client, bool notify_guc)
>  	/* Doorbell release flow requires that we wait for GEN8_DRB_VALID bit
>  	 * to go to zero after updating db_status before we call the GuC to
>  	 * release the doorbell */
> -	if (wait_for_us(!(I915_READ(GEN8_DRBREGL(db_id)) & GEN8_DRB_VALID),  
> 10))
> +	if (wait_for_us(!(I915_READ(GEN8_DRBREGL(db_id)) & GEN8_DRB_VALID),
> +			50))

Can we use intel_wait_for_register() here ?

>  		WARN_ONCE(true, "Doorbell never became invalid after disable\n");
> 	if (notify_guc)