drm/amdgpu: retry init if it fails due to exclusive mode timeout (v3)

The exclusive mode has real-time limitation in reality, such like being
done in 300ms. It's easy observed if running many VF/VMs in single host
with heavy CPU workload.

If we find the init fails due to exclusive mode timeout, try it again.

v2:
 - rewrite the condition for readable value.

v3:
 - fix typo, add comments for sleep

Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: pding <Pixel.Ding@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
index 720139e182a3..f313eee60c4a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -86,7 +86,7 @@ done_free:
 int amdgpu_driver_load_kms(struct drm_device *dev, unsigned long flags)
 {
         struct amdgpu_device *adev;
-        int r, acpi_status;
+        int r, acpi_status, retry = 0;
 
 #ifdef CONFIG_DRM_AMDGPU_SI
         if (!amdgpu_si_support) {
@@ -122,6 +122,7 @@ int amdgpu_driver_load_kms(struct drm_device *dev, unsigned long flags)
                 }
         }
 #endif
+retry_init:
 
         adev = kzalloc(sizeof(struct amdgpu_device), GFP_KERNEL);
         if (adev == NULL) {
@@ -144,7 +145,17 @@ int amdgpu_driver_load_kms(struct drm_device *dev, unsigned long flags)
          * VRAM allocation
          */
         r = amdgpu_device_init(adev, dev, dev->pdev, flags);
-        if (r) {
+        if (r == -EAGAIN && ++retry <= 3) {
+                adev->virt.caps &= ~AMDGPU_SRIOV_CAPS_RUNTIME;
+                adev->virt.ops = NULL;
+                amdgpu_device_fini(adev);
+                kfree(adev);
+                dev->dev_private = NULL;
+                /* Don't request EX mode too frequently which is attacking */
+                msleep(5000);
+                dev_err(&dev->pdev->dev, "retry init %d\n", retry);
+                goto retry_init;
+        } else if (r) {
                 dev_err(&dev->pdev->dev, "Fatal error during GPU init\n");
                 goto out;
         }