Re: [PATCH] drm/i915/guc/slpc: Use non-blocking H2G for waitboost

On Wed, 22 Jun 2022 17:32:25 -0700, Vinay Belgaumkar wrote:

@@ -208,12 +232,14 @@ static int slpc_force_min_freq(struct intel_guc_slpc *slpc, u32 freq) */

with_intel_runtime_pm(&i915->runtime_pm, wakeref) {

• ret = slpc_set_param(slpc,
  

• 		     SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ,
  

• 		     freq);
  

• /* Non-blocking request will avoid stalls */
  

• ret = slpc_set_param_nb(slpc,
  

• 			SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ,
  

• 			freq);
  

  if (ret)

• 	i915_probe_error(i915, "Unable to force min freq to %u: %d",
  

• 			 freq, ret);
  

• 	drm_notice(&i915->drm,
  

• 		   "Failed to send set_param for min freq(%d): (%d)\n",
  

• 		   freq, ret);
  

I am still thinking if we should replace drm_notice() by i915_probe_error() since drm_notice() will basically hide any issues of boost/de-boost's getting dropped.

Another idea here might be to maintain a counter, say "slpc->failed_boosts" which we increment each time slpc_set_param_nb() fails and dump that counter via intel_guc_slpc_print_info().

Anyway for now this is:

Reviewed-by: Ashutosh Dixit ashutosh.dixit@intel.com