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;
}
