drm/panthor: Report innocent group kill

Groups can be killed during a reset even though they did nothing wrong.
That usually happens when the FW is put in a bad state by other groups,
resulting in group suspension failures when the reset happens.

If we end up in that situation, flag the group innocent and report
innocence through a new DRM_PANTHOR_GROUP_STATE flag.

Bump the minor driver version to reflect the uAPI change.

Changes in v4:
- Add an entry to the driver version changelog
- Add R-bs

Changes in v3:
- Actually report innocence to userspace

Changes in v2:
- New patch

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241211080500.2349505-1-boris.brezillon@collabora.com

diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index 33cfba87752543de180b99c9186a544311cef1f1..d5dcd3d1b33a0ec29a1b304f4ee37839bfb1704f 100644 (file)
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -1493,6 +1493,7 @@ static void panthor_debugfs_init(struct drm_minor *minor)
  * - 1.1 - adds DEV_QUERY_TIMESTAMP_INFO query
  * - 1.2 - adds DEV_QUERY_GROUP_PRIORITIES_INFO query
  *       - adds PANTHOR_GROUP_PRIORITY_REALTIME priority
+ * - 1.3 - adds DRM_PANTHOR_GROUP_STATE_INNOCENT flag
  */
 static const struct drm_driver panthor_drm_driver = {
        .driver_features = DRIVER_RENDER | DRIVER_GEM | DRIVER_SYNCOBJ |
@@ -1506,7 +1507,7 @@ static const struct drm_driver panthor_drm_driver = {
        .name = "panthor",
        .desc = "Panthor DRM driver",
        .major = 1,
-       .minor = 2,
+       .minor = 3,
 
        .gem_create_object = panthor_gem_create_object,
        .gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table,

diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
index 58200d299fbb729ffa3b48c92a64353d09b83432..77b184c3fb0cec9554de09f8df64d4b5a136ea44 100644 (file)
--- a/drivers/gpu/drm/panthor/panthor_sched.c
+++ b/drivers/gpu/drm/panthor/panthor_sched.c
@@ -610,6 +610,16 @@ struct panthor_group {
         */
        bool timedout;
 
+       /**
+        * @innocent: True when the group becomes unusable because the group suspension
+        * failed during a reset.
+        *
+        * Sometimes the FW was put in a bad state by other groups, causing the group
+        * suspension happening in the reset path to fail. In that case, we consider the
+        * group innocent.
+        */
+       bool innocent;
+
        /**
         * @syncobjs: Pool of per-queue synchronization objects.
         *
@@ -2690,6 +2700,12 @@ void panthor_sched_suspend(struct panthor_device *ptdev)
                        u32 csg_id = ffs(slot_mask) - 1;
                        struct panthor_csg_slot *csg_slot = &sched->csg_slots[csg_id];
 
+                       /* If the group was still usable before that point, we consider
+                        * it innocent.
+                        */
+                       if (group_can_run(csg_slot->group))
+                               csg_slot->group->innocent = true;
+
                        /* We consider group suspension failures as fatal and flag the
                         * group as unusable by setting timedout=true.
                         */
@@ -3570,6 +3586,8 @@ int panthor_group_get_state(struct panthor_file *pfile,
                get_state->state |= DRM_PANTHOR_GROUP_STATE_FATAL_FAULT;
                get_state->fatal_queues = group->fatal_queues;
        }
+       if (group->innocent)
+               get_state->state |= DRM_PANTHOR_GROUP_STATE_INNOCENT;
        mutex_unlock(&sched->lock);
 
        group_put(group);

diff --git a/include/uapi/drm/panthor_drm.h b/include/uapi/drm/panthor_drm.h
index 87c9cb555dd1d19ba7e042203d38de0e74f69e05..b99763cbae48f6840e7bf9632f0e39e5e175565a 100644 (file)
--- a/include/uapi/drm/panthor_drm.h
+++ b/include/uapi/drm/panthor_drm.h
@@ -923,6 +923,15 @@ enum drm_panthor_group_state_flags {
         * When a group ends up with this flag set, no jobs can be submitted to its queues.
         */
        DRM_PANTHOR_GROUP_STATE_FATAL_FAULT = 1 << 1,
+
+       /**
+        * @DRM_PANTHOR_GROUP_STATE_INNOCENT: Group was killed during a reset caused by other
+        * groups.
+        *
+        * This flag can only be set if DRM_PANTHOR_GROUP_STATE_TIMEDOUT is set and
+        * DRM_PANTHOR_GROUP_STATE_FATAL_FAULT is not.
+        */
+       DRM_PANTHOR_GROUP_STATE_INNOCENT = 1 << 2,
 };
 
 /**