[Intel-gfx] [PATCH 08/18] drm/i915: Add a relay backed debugfs interface for capturing GuC logs

[Goel, Akash]

On 8/15/2016 9:42 PM, Chris Wilson wrote:
> On Mon, Aug 15, 2016 at 05:09:45PM +0100, Chris Wilson wrote:
>> On Mon, Aug 15, 2016 at 08:19:49PM +0530, akash.goel at intel.com wrote:
>>> +void i915_guc_register(struct drm_i915_private *dev_priv)
>>> +{
>>> +	if (!i915.enable_guc_submission)
>>> +		return;
>>
>> The final state of i915.enable_guc_submission is not known at this time.

As per the below sequence, i915.enable_guc_submission would have been 
set to its final value by this time,

i915_driver_load
	i915_load_modeset_init
		i915_gem_init_hw
			intel_guc_setup
				i915_guc_submission_init
				i915_guc_submission_enable
	i915_driver_register
		i915_debugfs_register
		i915_guc_register

>> Does it matter if you set up the log even though guc is not used?
>>
I think it would be better to do setup only if guc submission is enabled.

>> Would this not be better driver from guc_submission_enable and
>> guc_submission_disable?
>

> With the caveat that you probably need both. i.e. you have to wait for
> both the GuC to be enabled and for sysfs to be available.
Sorry I am really confused.
Isn't this a right location ? creating the relay file after the debugfs 
registration has been done.
Other logging related setup is being done at i915_guc_submission_init().

Best regards
Akash

> -Chris
>