Re: [PATCH] drm/amdgpu: Return error if no RAS

[Luben Tuikov <luben.tuikov@amd.com>]

On 2021-07-06 11:25 a.m., Alex Deucher wrote:
> On Fri, Jul 2, 2021 at 7:05 PM Luben Tuikov <luben.tuikov@amd.com> wrote:
>> In amdgpu_ras_query_error_count() return an error
>> if the device doesn't support RAS. This prevents
>> that function from having to always set the values
>> of the integer pointers (if set), and thus
>> prevents function side effects--always to have to
>> set values of integers if integer pointers set,
>> regardless of whether RAS is supported or
>> not--with this change this side effect is
>> mitigated.
>>
>> Also, if no pointers are set, don't count, since
>> we've no way of reporting the counts.
>>
>> Also, give this function a kernel-doc.
>>
>> Cc: Alexander Deucher <Alexander.Deucher@amd.com>
>> Cc: John Clements <john.clements@amd.com>
>> Cc: Hawking Zhang <Hawking.Zhang@amd.com>
>> Reported-by: Tom Rix <trix@redhat.com>
>> Fixes: a46751fbcde505 ("drm/amdgpu: Fix RAS function interface")
>> Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
>> ---
>>  drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 49 ++++++++++++++++++-------
>>  drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h |  6 +--
>>  2 files changed, 38 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
>> index c6ae63893dbdb2..ed698b2be79023 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
>> @@ -813,7 +813,7 @@ static int amdgpu_ras_enable_all_features(struct amdgpu_device *adev,
>>
>>  /* query/inject/cure begin */
>>  int amdgpu_ras_query_error_status(struct amdgpu_device *adev,
>> -       struct ras_query_if *info)
>> +                                 struct ras_query_if *info)
>>  {
>>         struct ras_manager *obj = amdgpu_ras_find_obj(adev, &info->head);
>>         struct ras_err_data err_data = {0, 0, 0, NULL};
>> @@ -1047,17 +1047,32 @@ int amdgpu_ras_error_inject(struct amdgpu_device *adev,
>>         return ret;
>>  }
>>
>> -/* get the total error counts on all IPs */
>> -void amdgpu_ras_query_error_count(struct amdgpu_device *adev,
>> -                                 unsigned long *ce_count,
>> -                                 unsigned long *ue_count)
>> +/**
>> + * amdgpu_ras_query_error_count -- Get error counts of all IPs
>> + * adev: pointer to AMD GPU device
>> + * ce_count: pointer to an integer to be set to the count of correctible errors.
>> + * ue_count: pointer to an integer to be set to the count of uncorrectible
>> + * errors.
>> + *
>> + * If set, @ce_count or @ue_count, count and return the corresponding
>> + * error counts in those integer pointers. Return 0 if the device
>> + * supports RAS. Return -EINVAL if the device doesn't support RAS.
>> + */
>> +int amdgpu_ras_query_error_count(struct amdgpu_device *adev,
>> +                                unsigned long *ce_count,
>> +                                unsigned long *ue_count)
>>  {
>>         struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
>>         struct ras_manager *obj;
>>         unsigned long ce, ue;
>>
>>         if (!adev->ras_enabled || !con)
>> -               return;
>> +               return -EINVAL;
> Maybe return -ENOTSUPP or -ENODEV here or something like that since
> the device doesn't support RAS in that case?  Other than that, looks
> good to me.
> Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

Okay, great. I thought about -ENODEV but didn't want to confuse the IOCTL/userspace that the device isn't there, so I'll then return -EOPNOTSUPP, add your R-B and push it.

Regards,
Luben

>
> Alex
>
>
>> +
>> +       /* Don't count since no reporting.
>> +        */
>> +       if (!ce_count && !ue_count)
>> +               return 0;
>>
>>         ce = 0;
>>         ue = 0;
>> @@ -1065,9 +1080,11 @@ void amdgpu_ras_query_error_count(struct amdgpu_device *adev,
>>                 struct ras_query_if info = {
>>                         .head = obj->head,
>>                 };
>> +               int res;
>>
>> -               if (amdgpu_ras_query_error_status(adev, &info))
>> -                       return;
>> +               res = amdgpu_ras_query_error_status(adev, &info);
>> +               if (res)
>> +                       return res;
>>
>>                 ce += info.ce_count;
>>                 ue += info.ue_count;
>> @@ -1078,6 +1095,8 @@ void amdgpu_ras_query_error_count(struct amdgpu_device *adev,
>>
>>         if (ue_count)
>>                 *ue_count = ue;
>> +
>> +       return 0;
>>  }
>>  /* query/inject/cure end */
>>
>> @@ -2145,9 +2164,10 @@ static void amdgpu_ras_counte_dw(struct work_struct *work)
>>
>>         /* Cache new values.
>>          */
>> -       amdgpu_ras_query_error_count(adev, &ce_count, &ue_count);
>> -       atomic_set(&con->ras_ce_count, ce_count);
>> -       atomic_set(&con->ras_ue_count, ue_count);
>> +       if (amdgpu_ras_query_error_count(adev, &ce_count, &ue_count) == 0) {
>> +               atomic_set(&con->ras_ce_count, ce_count);
>> +               atomic_set(&con->ras_ue_count, ue_count);
>> +       }
>>
>>         pm_runtime_mark_last_busy(dev->dev);
>>  Out:
>> @@ -2320,9 +2340,10 @@ int amdgpu_ras_late_init(struct amdgpu_device *adev,
>>
>>         /* Those are the cached values at init.
>>          */
>> -       amdgpu_ras_query_error_count(adev, &ce_count, &ue_count);
>> -       atomic_set(&con->ras_ce_count, ce_count);
>> -       atomic_set(&con->ras_ue_count, ue_count);
>> +       if (amdgpu_ras_query_error_count(adev, &ce_count, &ue_count) == 0) {
>> +               atomic_set(&con->ras_ce_count, ce_count);
>> +               atomic_set(&con->ras_ue_count, ue_count);
>> +       }
>>
>>         return 0;
>>  cleanup:
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h
>> index 283afd791db107..4d9c63f2f37718 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h
>> @@ -491,9 +491,9 @@ int amdgpu_ras_request_reset_on_boot(struct amdgpu_device *adev,
>>  void amdgpu_ras_resume(struct amdgpu_device *adev);
>>  void amdgpu_ras_suspend(struct amdgpu_device *adev);
>>
>> -void amdgpu_ras_query_error_count(struct amdgpu_device *adev,
>> -                                 unsigned long *ce_count,
>> -                                 unsigned long *ue_count);
>> +int amdgpu_ras_query_error_count(struct amdgpu_device *adev,
>> +                                unsigned long *ce_count,
>> +                                unsigned long *ue_count);
>>
>>  /* error handling functions */
>>  int amdgpu_ras_add_bad_pages(struct amdgpu_device *adev,
>> --
>> 2.32.0
>>
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