[PATCH v10 4/4] drm/amdgpu: fix fence fallback timer expired error

[Samuel Zhang]

IH is not working after switching a new gpu index for the first time.

During VM resume, QEMU programming of VF MSIX table (register GFXMSIX_VECT0_ADDR_LO)
may not work.The access could be blocked by nBIF protection as VF isn't in
exclusive access mode. Exclusive access is enabled now, disable/enable MSIX
so that QEMU reprograms MSIX table.

call amdgpu_restore_msix on resume to restore msix table.

Signed-off-by: Samuel Zhang <guoqing.zhang at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 7 +++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c    | 2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h    | 1 +
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 0246a33b90af..f67bc9a52d53 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -5051,6 +5051,13 @@ static inline int amdgpu_virt_resume(struct amdgpu_device *adev)
 	int r;
 	unsigned int prev_physical_node_id = adev->gmc.xgmi.physical_node_id;
 
+	/* During VM resume, QEMU programming of VF MSIX table (register GFXMSIX_VECT0_ADDR_LO)
+	 * may not work. The access could be blocked by nBIF protection as VF isn't in
+	 * exclusive access mode. Exclusive access is enabled now, disable/enable MSIX
+	 * so that QEMU reprograms MSIX table.
+	 */
+	amdgpu_restore_msix(adev);
+
 	r = adev->gfxhub.funcs->get_xgmi_info(adev);
 	if (r)
 		return r;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
index 0e890f2785b1..f080354efec8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
@@ -245,7 +245,7 @@ static bool amdgpu_msi_ok(struct amdgpu_device *adev)
 	return true;
 }
 
-static void amdgpu_restore_msix(struct amdgpu_device *adev)
+void amdgpu_restore_msix(struct amdgpu_device *adev)
 {
 	u16 ctrl;
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h
index aef5c216b191..f52bd7e6d988 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h
@@ -149,5 +149,6 @@ void amdgpu_irq_gpu_reset_resume_helper(struct amdgpu_device *adev);
 int amdgpu_irq_add_domain(struct amdgpu_device *adev);
 void amdgpu_irq_remove_domain(struct amdgpu_device *adev);
 unsigned amdgpu_irq_create_mapping(struct amdgpu_device *adev, unsigned src_id);
+void amdgpu_restore_msix(struct amdgpu_device *adev);
 
 #endif
-- 
2.43.5