Re: [PATCH] drm/amdgpu: Ignore first evction failure during suspend

["Christian König" <ckoenig.leichtzumerken@gmail.com>]

When amdgpu_device_suspend() is called processes should be frozen 
already. In other words KFD queues etc... should already be idle.

So when the eviction fails here we missed something previously and that 
in turn can cause tons amount of problems.

So ignoring those errors is most likely not a good idea at all.

Regards,
Christian.

Am 12.09.23 um 02:21 schrieb Pan, Xinhui:
> [AMD Official Use Only - General]
>
> Oh yep, Pinned BO is moved to other LRU list, So eviction fails because of other reason.
> I will change the comments in the patch.
> The problem is eviction fails as many reasons, say, BO is locked.
> ASAIK, kfd will stop the queues and flush some evict/restore work in its suspend callback. SO the first eviction before kfd callback likely fails.
>
> -----Original Message-----
> From: Christian König <ckoenig.leichtzumerken@gmail.com>
> Sent: Friday, September 8, 2023 2:49 PM
> To: Pan, Xinhui <Xinhui.Pan@amd.com>; amd-gfx@lists.freedesktop.org
> Cc: Deucher, Alexander <Alexander.Deucher@amd.com>; Koenig, Christian <Christian.Koenig@amd.com>; Fan, Shikang <Shikang.Fan@amd.com>
> Subject: Re: [PATCH] drm/amdgpu: Ignore first evction failure during suspend
>
> Am 08.09.23 um 05:39 schrieb xinhui pan:
>> Some BOs might be pinned. So the first eviction's failure will abort
>> the suspend sequence. These pinned BOs will be unpined afterwards
>> during suspend.
> That doesn't make much sense since pinned BOs don't cause eviction failure here.
>
> What exactly is the error code you see?
>
> Christian.
>
>> Actaully it has evicted most BOs, so that should stil work fine in
>> sriov full access mode.
>>
>> Fixes: 47ea20762bb7 ("drm/amdgpu: Add an extra evict_resource call
>> during device_suspend.")
>> Signed-off-by: xinhui pan <xinhui.pan@amd.com>
>> ---
>>    drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 9 +++++----
>>    1 file changed, 5 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> index 5c0e2b766026..39af526cdbbe 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> @@ -4148,10 +4148,11 @@ int amdgpu_device_suspend(struct drm_device
>> *dev, bool fbcon)
>>
>>        adev->in_suspend = true;
>>
>> -     /* Evict the majority of BOs before grabbing the full access */
>> -     r = amdgpu_device_evict_resources(adev);
>> -     if (r)
>> -             return r;
>> +     /* Try to evict the majority of BOs before grabbing the full access
>> +      * Ignore the ret val at first place as we will unpin some BOs if any
>> +      * afterwards.
>> +      */
>> +     (void)amdgpu_device_evict_resources(adev);
>>
>>        if (amdgpu_sriov_vf(adev)) {
>>                amdgpu_virt_fini_data_exchange(adev);