Re: [PATCH 2/2] drm/amdgpu: add AMDGPURESET uevent on AMD GPU reset

[Christian König]

Am 17.01.22 um 07:33 schrieb Somalapuram Amaranath:
AMDGPURESET uevent added to notify userspace, collect dump_stack and trace
Signed-off-by: Somalapuram Amaranath <amaranath.somalapu...@amd.com>
---
  drivers/gpu/drm/amd/amdgpu/nv.c | 45 +++++++++++++++++++++++++++++++++
  1 file changed, 45 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/nv.c b/drivers/gpu/drm/amd/amdgpu/nv.c
index 2ec1ffb36b1f..b73147ae41fb 100644
--- a/drivers/gpu/drm/amd/amdgpu/nv.c
+++ b/drivers/gpu/drm/amd/amdgpu/nv.c
@@ -529,10 +529,55 @@ nv_asic_reset_method(struct amdgpu_device *adev)
        }
  }
  
+/**
+ * drm_sysfs_reset_event - generate a DRM uevent
+ * @dev: DRM device
+ *
+ * Send a uevent for the DRM device specified by @dev.  Currently we only
+ * set AMDGPURESET=1 in the uevent environment, but this could be expanded to
+ * deal with other types of events.
+ *
+ * Any new uapi should be using the drm_sysfs_connector_status_event()
+ * for uevents on connector status change.
+ */
+void drm_sysfs_reset_event(struct drm_device *dev)

This should probably go directly into the DRM subsystem.

+{
+       char *event_string = "AMDGPURESET=1";
+       char *envp[2] = { event_string, NULL };
+
+       kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);

As I said this approach is a clear NAK. We can't allocate any memory 
when we do a reset.

Regards,
Christian.

+}
+
+void amdgpu_reset_dumps(struct amdgpu_device *adev)
+{
+       struct drm_device *ddev = adev_to_drm(adev);
+       int r = 0, i;
+
+       /* original raven doesn't have full asic reset */
+       if ((adev->apu_flags & AMD_APU_IS_RAVEN) &&
+               !(adev->apu_flags & AMD_APU_IS_RAVEN2))
+               return;
+       for (i = 0; i < adev->num_ip_blocks; i++) {
+               if (!adev->ip_blocks[i].status.valid)
+                       continue;
+               if (!adev->ip_blocks[i].version->funcs->reset_reg_dumps)
+                       continue;
+               r = adev->ip_blocks[i].version->funcs->reset_reg_dumps(adev);
+
+               if (r)
+                       DRM_ERROR("reset_reg_dumps of IP block <%s> failed 
%d\n",
+                                       
adev->ip_blocks[i].version->funcs->name, r);
+       }
+
+       drm_sysfs_reset_event(ddev);
+       dump_stack();
+}
+
  static int nv_asic_reset(struct amdgpu_device *adev)
  {
        int ret = 0;
  
+	amdgpu_reset_dumps(adev);
        switch (nv_asic_reset_method(adev)) {
        case AMD_RESET_METHOD_PCI:
                dev_info(adev->dev, "PCI reset\n");