[Intel-gfx] [PATCH v2] drm/i915/huc: Fix error reported by I915_PARAM_HUC_STATUS

[Ye, Tony]

On 2/26/2020 6:02 AM, Michal Wajdeczko wrote:
> 
> 
> On 25.02.2020 08:49, Ye, Tony wrote:
>>
>>
>> On 2/21/2020 11:32 PM, 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.
>>>
>>> v2: use 0 only for disabled, add more error codes for other failures
>>>
>>> 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>
>>> Cc: Robert M. Fosha <robert.m.fosha at intel.com>
>>> Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com> #v1
>>> ---
>>>    drivers/gpu/drm/i915/gt/uc/intel_huc.c | 29 +++++++++++++++++++++-----
>>>    1 file changed, 24 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_huc.c
>>> b/drivers/gpu/drm/i915/gt/uc/intel_huc.c
>>> index a74b65694512..301bb5d5e59a 100644
>>> --- a/drivers/gpu/drm/i915/gt/uc/intel_huc.c
>>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_huc.c
>>> @@ -200,9 +200,13 @@ int intel_huc_auth(struct intel_huc *huc)
>>>     * This function reads status register to verify if HuC
>>>     * firmware was successfully loaded.
>>>     *
>>> - * Returns: 1 if HuC firmware is loaded and verified,
>>> - * 0 if HuC firmware is not loaded and -ENODEV if HuC
>>> - * is not present on this platform.
>>> + * Returns:
>>> + *  * 1 if HuC firmware is loaded and verified,
>>> + *  * 0 if HuC firmware was disabled,
>>> + *  * -ENODEV if HuC is not present on this platform,
>>> + *  * -ENOPKG if HuC firmware was not installed,
>>> + *  * -ENOEXEC if HuC firmware is invalid,
>>> + *  * -EACCES if HuC firmware was not authenticated.
>>>     */
>>>    int intel_huc_check_status(struct intel_huc *huc)
>>>    {
>>> @@ -210,11 +214,26 @@ int intel_huc_check_status(struct intel_huc *huc)
>>>        intel_wakeref_t wakeref;
>>>        u32 status = 0;
>>>    -    if (!intel_huc_is_supported(huc))
>>> +    if (!HAS_GT_UC(gt->i915))
>>>            return -ENODEV;
>>>    +    switch (__intel_uc_fw_status(&huc->fw)) {
>>> +    case INTEL_UC_FIRMWARE_NOT_SUPPORTED:
>>> +    case INTEL_UC_FIRMWARE_DISABLED:
>>> +        return 0;
>>> +    case INTEL_UC_FIRMWARE_MISSING:
>>> +        return -ENOPKG;
>>> +    case INTEL_UC_FIRMWARE_ERROR:
>>> +        return -ENOEXEC;
>>
>> What about INTEL_UC_FIRMWARE_FAIL?
> 
> I assumed that we don't need to handle that case here, since we are
> still checking HuC status register below.
> 
> But if you want we can improve:
> 1) return early if FAIL, then check register anyway
> 2) return early if FAIL, trust fw state and return 1 without checking
> register (as same register was already checked when we mark fw state as
> RUNNING)

The current version looks good to me. Thanks.

Reviewed-by: Tony Ye <tony.ye at intel.com>

> 
>>
>> Regards,
>> Tony
>>
>>> +    default:
>>> +        break;
>>> +    }
>>> +
>>>        with_intel_runtime_pm(gt->uncore->rpm, wakeref)
>>>            status = intel_uncore_read(gt->uncore, huc->status.reg);
>>>    -    return (status & huc->status.mask) == huc->status.value;
>>> +    if ((status & huc->status.mask) != huc->status.value)
>>> +        return -EACCES;
>>> +
>>> +    return 1;
>>>    }
>>>