[PATCH v4 1/9] drm: Add a vendor-specific recovery method to device wedged uevent

[Riana Tauro]

Certain errors can cause the device to be wedged and may
require a vendor specific recovery method to restore normal
operation.

Add a recovery method 'WEDGED=vendor-specific' for such errors. Vendors
must provide additional recovery documentation if this method
is used.

v2: fix documentation (Raag)

Cc: André Almeida <andrealmeid at igalia.com>
Cc: Christian König <christian.koenig at amd.com>
Cc: David Airlie <airlied at gmail.com>
Cc: <dri-devel at lists.freedesktop.org>
Suggested-by: Raag Jadav <raag.jadav at intel.com>
Signed-off-by: Riana Tauro <riana.tauro at intel.com>
---
 Documentation/gpu/drm-uapi.rst | 9 +++++----
 drivers/gpu/drm/drm_drv.c      | 2 ++
 include/drm/drm_device.h       | 4 ++++
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/Documentation/gpu/drm-uapi.rst b/Documentation/gpu/drm-uapi.rst
index 263e5a97c080..c33070bdb347 100644
--- a/Documentation/gpu/drm-uapi.rst
+++ b/Documentation/gpu/drm-uapi.rst
@@ -421,10 +421,10 @@ Recovery
 Current implementation defines three recovery methods, out of which, drivers
 can use any one, multiple or none. Method(s) of choice will be sent in the
 uevent environment as ``WEDGED=<method1>[,..,<methodN>]`` in order of less to
-more side-effects. If driver is unsure about recovery or method is unknown
-(like soft/hard system reboot, firmware flashing, physical device replacement
-or any other procedure which can't be attempted on the fly), ``WEDGED=unknown``
-will be sent instead.
+more side-effects. If recovery method is specific to vendor
+``WEDGED=vendor-specific`` will be sent and userspace should refer to vendor
+specific documentation for further recovery steps. If driver is unsure about
+recovery or method is unknown, ``WEDGED=unknown`` will be sent instead
 
 Userspace consumers can parse this event and attempt recovery as per the
 following expectations.
@@ -435,6 +435,7 @@ following expectations.
     none            optional telemetry collection
     rebind          unbind + bind driver
     bus-reset       unbind + bus reset/re-enumeration + bind
+    vendor-specific vendor specific recovery method
     unknown         consumer policy
     =============== ========================================
 
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index cdd591b11488..0ac723a46a91 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -532,6 +532,8 @@ static const char *drm_get_wedge_recovery(unsigned int opt)
 		return "rebind";
 	case DRM_WEDGE_RECOVERY_BUS_RESET:
 		return "bus-reset";
+	case DRM_WEDGE_RECOVERY_VENDOR:
+		return "vendor-specific";
 	default:
 		return NULL;
 	}
diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
index 08b3b2467c4c..08a087f149ff 100644
--- a/include/drm/drm_device.h
+++ b/include/drm/drm_device.h
@@ -26,10 +26,14 @@ struct pci_controller;
  * Recovery methods for wedged device in order of less to more side-effects.
  * To be used with drm_dev_wedged_event() as recovery @method. Callers can
  * use any one, multiple (or'd) or none depending on their needs.
+ *
+ * Refer to "Device Wedging" chapter in Documentation/gpu/drm-uapi.rst for more
+ * details.
  */
 #define DRM_WEDGE_RECOVERY_NONE		BIT(0)	/* optional telemetry collection */
 #define DRM_WEDGE_RECOVERY_REBIND	BIT(1)	/* unbind + bind driver */
 #define DRM_WEDGE_RECOVERY_BUS_RESET	BIT(2)	/* unbind + reset bus device + bind */
+#define DRM_WEDGE_RECOVERY_VENDOR	BIT(3)	/* vendor specific recovery method */
 
 /**
  * struct drm_wedge_task_info - information about the guilty task of a wedge dev
-- 
2.47.1