[Intel-gfx] [PATCH] drm/i915/huc: Don't try to check HuC status if it's not loaded

[Michal Wajdeczko]

On Fri, 17 May 2019 23:52:37 +0200, Chris Wilson  
<chris at chris-wilson.co.uk> wrote:

> Quoting Michal Wajdeczko (2019-05-17 22:40:28)
>> If we never attempted to load HuC firmware, or we already wedged
>> or reset GuC/HuC, then there is no reason to wake up the device
>> to check one bit in the register that will be for sure cleared.
>>
>> Suggested-by: Chris Wilson <chris at chris-wilson.co.uk>
>> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
>> Cc: Chris Wilson <chris at chris-wilson.co.uk>
>> Cc: Tony Ye <tony.ye at intel.com>
>> ---
>>  drivers/gpu/drm/i915/intel_huc.c | 3 +++
>>  drivers/gpu/drm/i915/intel_huc.h | 5 +++++
>>  2 files changed, 8 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_huc.c  
>> b/drivers/gpu/drm/i915/intel_huc.c
>> index 1ff1fb015e58..9d91089e2cd1 100644
>> --- a/drivers/gpu/drm/i915/intel_huc.c
>> +++ b/drivers/gpu/drm/i915/intel_huc.c
>> @@ -163,6 +163,9 @@ int intel_huc_check_status(struct intel_huc *huc)
>>         if (!HAS_HUC(dev_priv))
>>                 return -ENODEV;
>>
>> +       if (!intel_huc_is_loaded(huc))
>> +               return 0;
>
> Just to throw out an idea, -ENXIO?
>
> A subtle change in ABI that should go unnoticed by the media driver, but
> helps differentiate cause without having to dig deeper.

or maybe:

	if (!USES_HUC(dev_priv))
		return 0;

	if (!intel_huc_is_loaded(huc))
		return -ENXIO;

	...