From 6623c5f9fd877868fba133b4ae4dab0052e82dad Mon Sep 17 00:00:00 2001 From: "Jesse.Zhang" Date: Fri, 24 Oct 2025 16:09:25 +0800 Subject: [PATCH] drm/amdgpu: fix lock warning in amdgpu_userq_fence_driver_process MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Fix a potential deadlock caused by inconsistent spinlock usage between interrupt and process contexts in the userq fence driver. The issue occurs when amdgpu_userq_fence_driver_process() is called from both: - Interrupt context: gfx_v11_0_eop_irq() -> amdgpu_userq_fence_driver_process() - Process context: amdgpu_eviction_fence_suspend_worker() -> amdgpu_userq_fence_driver_force_completion() -> amdgpu_userq_fence_driver_process() In interrupt context, the spinlock was acquired without disabling interrupts, leaving it in {IN-HARDIRQ-W} state. When the same lock is acquired in process context, the kernel detects inconsistent locking since the process context acquisition would enable interrupts while holding a lock previously acquired in interrupt context. Kernel log shows: [ 4039.310790] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. [ 4039.310804] kworker/7:2/409 [HC0[0]:SC0[0]:HE1:SE1] takes: [ 4039.310818] ffff9284e1bed000 (&fence_drv->fence_list_lock){?...}-{3:3}, [ 4039.310993] {IN-HARDIRQ-W} state was registered at: [ 4039.311004] lock_acquire+0xc6/0x300 [ 4039.311018] _raw_spin_lock+0x39/0x80 [ 4039.311031] amdgpu_userq_fence_driver_process.part.0+0x30/0x180 [amdgpu] [ 4039.311146] amdgpu_userq_fence_driver_process+0x17/0x30 [amdgpu] [ 4039.311257] gfx_v11_0_eop_irq+0x132/0x170 [amdgpu] Fix by using spin_lock_irqsave()/spin_unlock_irqrestore() to properly manage interrupt state regardless of calling context. Reviewed-by: Christian König Signed-off-by: Jesse Zhang Signed-off-by: Alex Deucher (cherry picked from commit ded3ad780cf97a04927773c4600823b84f7f3cc2) Cc: stable@vger.kernel.org --- drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c index 761bad98da3ec..4d0096d0baa9d 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c @@ -151,15 +151,16 @@ void amdgpu_userq_fence_driver_process(struct amdgpu_userq_fence_driver *fence_d { struct amdgpu_userq_fence *userq_fence, *tmp; struct dma_fence *fence; + unsigned long flags; u64 rptr; int i; if (!fence_drv) return; + spin_lock_irqsave(&fence_drv->fence_list_lock, flags); rptr = amdgpu_userq_fence_read(fence_drv); - spin_lock(&fence_drv->fence_list_lock); list_for_each_entry_safe(userq_fence, tmp, &fence_drv->fences, link) { fence = &userq_fence->base; @@ -174,7 +175,7 @@ void amdgpu_userq_fence_driver_process(struct amdgpu_userq_fence_driver *fence_d list_del(&userq_fence->link); dma_fence_put(fence); } - spin_unlock(&fence_drv->fence_list_lock); + spin_unlock_irqrestore(&fence_drv->fence_list_lock, flags); } void amdgpu_userq_fence_driver_destroy(struct kref *ref) -- 2.47.3