[Intel-gfx] [PATCH] drm/i915/huc: Fix error reported by I915_PARAM_HUC_STATUS

[Michal Wajdeczko]

On Thu, 23 Jan 2020 19:26:58 +0100, Ye, Tony <tony.ye at intel.com> wrote:

>
>
> On 1/23/2020 7:38 AM, Michal Wajdeczko wrote:
>> On Thu, 23 Jan 2020 16:02:17 +0100, Chris Wilson  
>> <chris at chris-wilson.co.uk> wrote:
>>
>>> Quoting Daniele Ceraolo Spurio (2020-01-22 23:52:33)
>>>>
>>>>
>>>> On 1/22/20 11:48 AM, Michal Wajdeczko wrote:
>>>> >  From commit 84b1ca2f0e68 ("drm/i915/uc: prefer intel_gt over i915
>>>> > in GuC/HuC paths") we stopped using HUC_STATUS error -ENODEV only
>>>> > to indicate lack of HuC hardware and we started to use this error
>>>> > also for all other cases when HuC was not in use or supported.
>>>> >
>>>> > Fix that by relying again on HAS_GT_UC macro, since currently
>>>> > used function intel_huc_is_supported() is based on HuC firmware
>>>> > support which could be unsupported also due to force disabled
>>>> > GuC firmware.
>>>> >
>>>> > Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
>>>> > Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
>>>> > Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
>>>> > Cc: Tony Ye <tony.ye at intel.com>
>>>>
>>>> Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
>>>
>>> Once upon a time did you (Michal) not argue we should indicate the lack
>>> of firmware in the error code? Something like
>>>
>>> if (!HAS_GT_UC(gt->i915))
>>>     return -ENODEV;
>>>
>>> if (!intel_huc_is_supported(huc))
>>>     return -ENOEXEC;
>>  Yes, we discussed this here [1] together with [2] but we didn't
>> conclude our discussion due to different opinions on how represent
>> some states, in particular "manually disabled" state.
>>  In this patch I just wanted to restore old notation.
>>  But we can start new discussion, here is summary:
>>  ------------------+----------+----------+----------
>>   HuC state        | today*   | option A | option B
>> ------------------+----------+----------+----------
>> no HuC hardware   | -ENODEV  | -ENODEV  | -ENODEV
>> GuC fw disabled   |   0      |     0    | -EOPNOTSUPP
>> HuC fw disabled   |   0      |     0    | -EOPNOTSUPP
>> HuC fw missing    |   0      | -ENOPKG  | -ENOEXEC
>> HuC fw error      |   0      | -ENOEXEC | -ENOEXEC
>> HuC fw fail       |   0      | -EACCES  |    0
>
> What is the difference of HuC fw error and HuC fw fail here?

see corresponding internal fw status codes:

	INTEL_UC_FIRMWARE_ERROR, /* invalid format or version */
	INTEL_UC_FIRMWARE_FAIL, /* failed to xfer or init/auth the fw */

>
> Regards,
> Tony
>
>> HuC authenticated |   1      |     1    |    1
>> ------------------+----------+----------+----------
>>  Note that all above should be compatible with media driver,
>> which explicitly looks for no error and value 1
>>  Michal
>>  [1] https://patchwork.freedesktop.org/patch/306419/?series=61001&rev=1
>> [2] https://patchwork.freedesktop.org/series/60800/#rev1