[Intel-gfx] [PATCH] drm/i915: Stop sleeping from inside gen6_bsd_submit_request()

[Michal Wajdeczko]

On Mon, Apr 10, 2017 at 03:38:07PM +0100, Chris Wilson wrote:
> submit_request() is called from an atomic context, it's not allowed to
> sleep. We have to be careful in our parameters to
> intel_uncore_wait_for_register() to limit ourselves to the atomic wait
> loop and not incur the wrath of our warnings.
> 
> Fixes: 6976e74b5fa1 ("drm/i915: Don't allow overuse of __intel_wait_for_register_fw()")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_ringbuffer.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index c98acc27279a..331da59a1eb5 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -1729,11 +1729,11 @@ static void gen6_bsd_submit_request(struct drm_i915_gem_request *request)
>  	I915_WRITE64_FW(GEN6_BSD_RNCID, 0x0);
>  
>  	/* Wait for the ring not to be idle, i.e. for it to wake up. */
> -	if (intel_wait_for_register_fw(dev_priv,
> -				       GEN6_BSD_SLEEP_PSMI_CONTROL,
> -				       GEN6_BSD_SLEEP_INDICATOR,
> -				       0,
> -				       50))
> +	if (__intel_wait_for_register_fw(dev_priv,
> +					 GEN6_BSD_SLEEP_PSMI_CONTROL,
> +					 GEN6_BSD_SLEEP_INDICATOR,
> +					 0,
> +					 1000, 0, NULL))

1000us will still cause __intel_wait_for_register_fw to complain. Limit is 10us.

-Michal

>  		DRM_ERROR("timed out waiting for the BSD ring to wake up\n");
>  
>  	/* Now that the ring is fully powered up, update the tail */
> -- 
> 2.11.0
>