[PATCH] drm/amdgpu: only WARN freeing buffers when DMA is unavailable

[Xiao, Jack]

[AMD Official Use Only - General]

                              >> >> It's simply not allowed to free up resources during suspend since those can't be acquired again during resume.
                              >> The in_suspend flag is set at the beginning of suspend and unset at the end of resume. It can't filter the case you mentioned.

               Why not? This is exactly what it should do.

[Jack] If freeing up resources during resume, it should not hit the issue you described. But only checking in_suspend flag would take these cases as warning.

Regards,
Jack

From: Koenig, Christian <Christian.Koenig at amd.com>
Sent: Monday, February 6, 2023 4:06 PM
To: Xiao, Jack <Jack.Xiao at amd.com>; Christian König <ckoenig.leichtzumerken at gmail.com>; amd-gfx at lists.freedesktop.org; Deucher, Alexander <Alexander.Deucher at amd.com>
Subject: Re: [PATCH] drm/amdgpu: only WARN freeing buffers when DMA is unavailable

Am 06.02.23 um 08:23 schrieb Xiao, Jack:

[AMD Official Use Only - General]

>> Nope, that is not related to any hw state.

can use other flag.

>> It's simply not allowed to free up resources during suspend since those can't be acquired again during resume.
The in_suspend flag is set at the beginning of suspend and unset at the end of resume. It can't filter the case you mentioned.

Why not? This is exactly what it should do.

Do you know the root cause of these cases hitting the issue? So that we can get an exact point to warn the freeing up behavior.

Well the root cause are programming errors. See between suspending and resuming you should not allocate nor free memory.

Otherwise we can run into trouble. And this check here is one part of that, we should probably add another warning during allocation of memory. But this here is certainly correct.

Regards,
Christian.


Thanks,
Jack

From: Christian König <ckoenig.leichtzumerken at gmail.com><mailto:ckoenig.leichtzumerken at gmail.com>
Sent: Friday, February 3, 2023 9:20 PM
To: Xiao, Jack <Jack.Xiao at amd.com><mailto:Jack.Xiao at amd.com>; Koenig, Christian <Christian.Koenig at amd.com><mailto:Christian.Koenig at amd.com>; amd-gfx at lists.freedesktop.org<mailto:amd-gfx at lists.freedesktop.org>; Deucher, Alexander <Alexander.Deucher at amd.com><mailto:Alexander.Deucher at amd.com>
Subject: Re: [PATCH] drm/amdgpu: only WARN freeing buffers when DMA is unavailable

Nope, that is not related to any hw state.

It's simply not allowed to free up resources during suspend since those can't be acquired again during resume.

We had a couple of cases now where this was wrong. If you get a warning from that please fix the code which tried to free something during suspend instead.

Regards,
Christian.
Am 03.02.23 um 07:04 schrieb Xiao, Jack:

[AMD Official Use Only - General]

>> It's simply illegal to free up memory during suspend.
Why? In my understanding, the limit was caused by DMA shutdown.

Regards,
Jack

From: Koenig, Christian <Christian.Koenig at amd.com><mailto:Christian.Koenig at amd.com>
Sent: Thursday, February 2, 2023 7:43 PM
To: Xiao, Jack <Jack.Xiao at amd.com><mailto:Jack.Xiao at amd.com>; amd-gfx at lists.freedesktop.org<mailto:amd-gfx at lists.freedesktop.org>; Deucher, Alexander <Alexander.Deucher at amd.com><mailto:Alexander.Deucher at amd.com>
Subject: AW: [PATCH] drm/amdgpu: only WARN freeing buffers when DMA is unavailable

Big NAK to this! This warning is not related in any way to the hw state.

It's simply illegal to free up memory during suspend.

Regards,
Christian.

________________________________
Von: Xiao, Jack <Jack.Xiao at amd.com<mailto:Jack.Xiao at amd.com>>
Gesendet: Donnerstag, 2. Februar 2023 10:54
An: amd-gfx at lists.freedesktop.org<mailto:amd-gfx at lists.freedesktop.org> <amd-gfx at lists.freedesktop.org<mailto:amd-gfx at lists.freedesktop.org>>; Deucher, Alexander <Alexander.Deucher at amd.com<mailto:Alexander.Deucher at amd.com>>; Koenig, Christian <Christian.Koenig at amd.com<mailto:Christian.Koenig at amd.com>>
Cc: Xiao, Jack <Jack.Xiao at amd.com<mailto:Jack.Xiao at amd.com>>
Betreff: [PATCH] drm/amdgpu: only WARN freeing buffers when DMA is unavailable

Reduce waringings, only warn when DMA is unavailable.

Signed-off-by: Jack Xiao <Jack.Xiao at amd.com<mailto:Jack.Xiao at amd.com>>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 2d237f3d3a2e..e3e3764ea697 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -422,7 +422,8 @@ void amdgpu_bo_free_kernel(struct amdgpu_bo **bo, u64 *gpu_addr,
         if (*bo == NULL)
                 return;

-       WARN_ON(amdgpu_ttm_adev((*bo)->tbo.bdev)->in_suspend);
+       WARN_ON(amdgpu_ttm_adev((*bo)->tbo.bdev)->in_suspend &&
+               !amdgpu_ttm_adev((*bo)->tbo.bdev)->ip_blocks[AMD_IP_BLOCK_TYPE_SDMA].status.hw);

         if (likely(amdgpu_bo_reserve(*bo, true) == 0)) {
                 if (cpu_addr)
--
2.37.3


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