This is a note to let you know that I've just added the patch titled drm/amdgpu: use spin_lock_irqsave to avoid deadlock by local interrupt to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-amdgpu-use-spin_lock_irqsave-to-avoid-deadlock-b.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 1078a53ddb07788f4791140faa1b7371c58ef3f4 Author: Guchun Chen <guchun.chen@xxxxxxx> Date: Fri Jan 7 16:31:20 2022 +0800 drm/amdgpu: use spin_lock_irqsave to avoid deadlock by local interrupt [ Upstream commit 2096b74b1da5ca418827b54ac4904493bd9de89c ] This is observed in SRIOV case with virtual KMS as display. _raw_spin_lock_irqsave+0x37/0x40 drm_handle_vblank+0x69/0x350 [drm] ? try_to_wake_up+0x432/0x5c0 ? amdgpu_vkms_prepare_fb+0x1c0/0x1c0 [amdgpu] drm_crtc_handle_vblank+0x17/0x20 [drm] amdgpu_vkms_vblank_simulate+0x4d/0x80 [amdgpu] __hrtimer_run_queues+0xfb/0x230 hrtimer_interrupt+0x109/0x220 __sysvec_apic_timer_interrupt+0x64/0xe0 asm_call_irq_on_stack+0x12/0x20 Fixes: 84ec374bd580 ("drm/amdgpu: create amdgpu_vkms (v4)") Signed-off-by: Guchun Chen <guchun.chen@xxxxxxx> Acked-by: Alex Deucher <alexander.deucher@xxxxxxx> Tested-by: Kelly Zytaruk <kelly.zytaruk@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c index ac9a8cd21c4b6..7d58bf410be05 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c @@ -142,15 +142,16 @@ static void amdgpu_vkms_crtc_atomic_disable(struct drm_crtc *crtc, static void amdgpu_vkms_crtc_atomic_flush(struct drm_crtc *crtc, struct drm_atomic_state *state) { + unsigned long flags; if (crtc->state->event) { - spin_lock(&crtc->dev->event_lock); + spin_lock_irqsave(&crtc->dev->event_lock, flags); if (drm_crtc_vblank_get(crtc) != 0) drm_crtc_send_vblank_event(crtc, crtc->state->event); else drm_crtc_arm_vblank_event(crtc, crtc->state->event); - spin_unlock(&crtc->dev->event_lock); + spin_unlock_irqrestore(&crtc->dev->event_lock, flags); crtc->state->event = NULL; }