[AMD Official Use Only] I wanted to keep the order the same as in amdgpu_device_lock_adev() (Set flag then acquire lock) to prevent any weird race conditions. Thanks, Victor -----Original Message----- From: Liu, Shaoyun <Shaoyun.Liu@xxxxxxx> Sent: Thursday, December 9, 2021 1:25 PM To: Skvortsov, Victor <Victor.Skvortsov@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx Cc: Skvortsov, Victor <Victor.Skvortsov@xxxxxxx> Subject: RE: [PATCH] drm/amdgpu: SRIOV flr_work should use down_write [AMD Official Use Only] I think it's a good catch for reset_sem, any reason to change the adev->in_gpu_reset ? Regards Shaoyun.liu -----Original Message----- From: amd-gfx <amd-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Victor Skvortsov Sent: Thursday, December 9, 2021 12:02 PM To: amd-gfx@xxxxxxxxxxxxxxxxxxxxx Cc: Skvortsov, Victor <Victor.Skvortsov@xxxxxxx> Subject: [PATCH] drm/amdgpu: SRIOV flr_work should use down_write Host initiated VF FLR may fail if someone else is already holding a read_lock. Change from down_write_trylock to down_write to guarantee the reset goes through. Signed-off-by: Victor Skvortsov <victor.skvortsov@xxxxxxx> --- drivers/gpu/drm/amd/amdgpu/mxgpu_ai.c | 5 +++-- drivers/gpu/drm/amd/amdgpu/mxgpu_nv.c | 5 +++-- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/mxgpu_ai.c b/drivers/gpu/drm/amd/amdgpu/mxgpu_ai.c index cd2719bc0139..e4365c97adaa 100644 --- a/drivers/gpu/drm/amd/amdgpu/mxgpu_ai.c +++ b/drivers/gpu/drm/amd/amdgpu/mxgpu_ai.c @@ -252,11 +252,12 @@ static void xgpu_ai_mailbox_flr_work(struct work_struct *work) * otherwise the mailbox msg will be ruined/reseted by * the VF FLR. */ - if (!down_write_trylock(&adev->reset_sem)) + if (atomic_cmpxchg(&adev->in_gpu_reset, 0, 1) != 0) return; + down_write(&adev->reset_sem); + amdgpu_virt_fini_vf2pf_work_item(adev); - atomic_set(&adev->in_gpu_reset, 1); xgpu_ai_mailbox_trans_msg(adev, IDH_READY_TO_RESET, 0, 0, 0); diff --git a/drivers/gpu/drm/amd/amdgpu/mxgpu_nv.c b/drivers/gpu/drm/amd/amdgpu/mxgpu_nv.c index 2bc93808469a..1cde70c72e54 100644 --- a/drivers/gpu/drm/amd/amdgpu/mxgpu_nv.c +++ b/drivers/gpu/drm/amd/amdgpu/mxgpu_nv.c @@ -281,11 +281,12 @@ static void xgpu_nv_mailbox_flr_work(struct work_struct *work) * otherwise the mailbox msg will be ruined/reseted by * the VF FLR. */ - if (!down_write_trylock(&adev->reset_sem)) + if (atomic_cmpxchg(&adev->in_gpu_reset, 0, 1) != 0) return; + down_write(&adev->reset_sem); + amdgpu_virt_fini_vf2pf_work_item(adev); - atomic_set(&adev->in_gpu_reset, 1); xgpu_nv_mailbox_trans_msg(adev, IDH_READY_TO_RESET, 0, 0, 0); -- 2.25.1
