From 942561cb8c14bc3008504d5f72894e09fc6e7e92 Mon Sep 17 00:00:00 2001
From: Guchun Chen <guchun.chen@amd.com>
Date: Fri, 7 Jan 2022 16:31:20 +0800
Subject: drm/amdgpu: use spin_lock_irqsave to avoid deadlock by local
 interrupt
Git-commit: 2096b74b1da5ca418827b54ac4904493bd9de89c
Patch-mainline: v5.17-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

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@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Tested-by: Kelly Zytaruk <kelly.zytaruk@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
index 2dcc68e04e84..d99c8779b51e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
@@ -144,15 +144,16 @@ 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;
 	}
-- 
2.38.1