[PATCH v5] drm/amdgpu: Restore msix after FLR

[Peng Ju Zhou]

From: "Emily.Deng" <Emily.Deng at amd.com>

After FLR, the msix will be cleared, so need to re-enable it.

Signed-off-by: Emily.Deng <Emily.Deng at amd.com>
Signed-off-by: Peng Ju Zhou <PengJu.Zhou at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
index 90f50561b43a..dbc0e5bb203d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
@@ -277,6 +277,21 @@ static bool amdgpu_msi_ok(struct amdgpu_device *adev)
 	return true;
 }
 
+static void amdgpu_restore_msix(struct amdgpu_device *adev)
+{
+	u16 ctrl;
+
+	pci_read_config_word(adev->pdev, adev->pdev->msix_cap + PCI_MSIX_FLAGS, &ctrl);
+	if (!(ctrl & PCI_MSIX_FLAGS_ENABLE))
+		return;
+
+	// re-set MSIX when VF FLR if VF MSIX enabled.
+	ctrl &= ~PCI_MSIX_FLAGS_ENABLE;
+	pci_write_config_word(adev->pdev, adev->pdev->msix_cap + PCI_MSIX_FLAGS, ctrl);
+	ctrl |= PCI_MSIX_FLAGS_ENABLE;
+	pci_write_config_word(adev->pdev, adev->pdev->msix_cap + PCI_MSIX_FLAGS, ctrl);
+}
+
 /**
  * amdgpu_irq_init - initialize interrupt handling
  *
@@ -558,6 +573,9 @@ void amdgpu_irq_gpu_reset_resume_helper(struct amdgpu_device *adev)
 {
 	int i, j, k;
 
+	if (amdgpu_sriov_vf(adev))
+		amdgpu_restore_msix(adev);
+
 	for (i = 0; i < AMDGPU_IRQ_CLIENTID_MAX; ++i) {
 		if (!adev->irq.client[i].sources)
 			continue;
-- 
2.17.1