[PATCH 7/9] drm/amdgpu:block kms open during gpu_reset

[Christian König]

> if we don't block device open while gpu doing recover, the vm init (SDMA working on page table creating) would be ruined by ASIC RESET
That is not a problem at all. SDMA just does some clear operation on the 
page tables and those are either recovered from the shadow or run after 
the reset.

Regards,
Christian.

Am 26.10.2017 um 10:17 schrieb Liu, Monk:
> When amdgpu_gpu_recover() routine is in the fly, we shouldn't let UMD open our device, otherwise the VM init would be ruined by gpu_recover().
>
> e.g. VM init need to create page table, but keep In mind that gpu_recover() calls ASIC RESET,
>
> if we don't block device open while gpu doing recover, the vm init (SDMA working on page table creating) would be ruined by ASIC RESET
>
> do you have any good solution ? the key point is avoid/delay/push_back hw activities from UMD side when we are running in gpu_recover() function
>
> BR Monk
>
> -----Original Message-----
> From: Christian König [mailto:ckoenig.leichtzumerken at gmail.com]
> Sent: 2017年10月26日 15:18
> To: Liu, Monk <Monk.Liu at amd.com>; amd-gfx at lists.freedesktop.org
> Subject: Re: [PATCH 7/9] drm/amdgpu:block kms open during gpu_reset
>
> NAK, why the heck should we do this? It would just block all new processes from using the device.
>
> Christian.
>
> Am 25.10.2017 um 11:22 schrieb Monk Liu:
>> Change-Id: Ibdb0ea9e3769d572fbbc13bbf1ef73f1af2ab7be
>> Signed-off-by: Monk Liu <Monk.Liu at amd.com>
>> ---
>>    drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c | 3 +++
>>    1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>> index 4a9f749..c155ce4 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>> @@ -813,6 +813,9 @@ int amdgpu_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)
>>    	if (r < 0)
>>    		return r;
>>    
>> +	if (adev->in_gpu_reset)
>> +		return -ENODEV;
>> +
>>    	fpriv = kzalloc(sizeof(*fpriv), GFP_KERNEL);
>>    	if (unlikely(!fpriv)) {
>>    		r = -ENOMEM;
>