From 9c51348f0dda749be267eec8da97c389d44adf27 Mon Sep 17 00:00:00 2001
From: Guchun Chen <guchun.chen@amd.com>
Date: Fri, 1 Oct 2021 09:48:50 +0800
Subject: drm/amdgpu: handle the case of pci_channel_io_frozen only in
amdgpu_pci_resume
Git-commit: 248b061689a40f4fed05252ee2c89f87cf26d7d8
Patch-mainline: v5.15-rc5
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
Alt-commit: e17e27f9bdba274b404454072302cf5ea2282e5d
In current code, when a PCI error state pci_channel_io_normal is detectd,
it will report PCI_ERS_RESULT_CAN_RECOVER status to PCI driver, and PCI
driver will continue the execution of PCI resume callback report_resume by
pci_walk_bridge, and the callback will go into amdgpu_pci_resume
finally, where write lock is releasd unconditionally without acquiring
such lock first. In this case, a deadlock will happen when other threads
start to acquire the read lock.
To fix this, add a member in amdgpu_device strucutre to cache
pci_channel_state, and only continue the execution in amdgpu_pci_resume
when it's pci_channel_io_frozen.
Fixes: c9a6b82f45e2 ("drm/amdgpu: Implement DPC recovery")
Suggested-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Guchun Chen <guchun.chen@amd.com>
Reviewed-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 +
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 6 ++++++
2 files changed, 7 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index d356e329e6f8..269437b01328 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1087,6 +1087,7 @@ struct amdgpu_device {
bool no_hw_access;
struct pci_saved_state *pci_state;
+ pci_channel_state_t pci_channel_state;
struct amdgpu_reset_control *reset_cntl;
};
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 53f3e07f6bd4..af9bdf16eefd 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -5399,6 +5399,8 @@ pci_ers_result_t amdgpu_pci_error_detected(struct pci_dev *pdev, pci_channel_sta
return PCI_ERS_RESULT_DISCONNECT;
}
+ adev->pci_channel_state = state;
+
switch (state) {
case pci_channel_io_normal:
return PCI_ERS_RESULT_CAN_RECOVER;
@@ -5541,6 +5543,10 @@ void amdgpu_pci_resume(struct pci_dev *pdev)
DRM_INFO("PCI error: resume callback!!\n");
+ /* Only continue execution for the case of pci_channel_io_frozen */
+ if (adev->pci_channel_state != pci_channel_io_frozen)
+ return;
+
for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
struct amdgpu_ring *ring = adev->rings[i];
--
2.38.1