On Wed, 11 Dec 2024 09:05:00 +0100
Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx> wrote:
> 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@xxxxxxxxxxxxx>
> Reviewed-by: Liviu Dudau <liviu.dudau@xxxxxxx>
> Reviewed-by: Steven Price <steven.price@xxxxxxx>
Queued to drm-misc-next.
> ---
> drivers/gpu/drm/panthor/panthor_drv.c | 3 ++-
> drivers/gpu/drm/panthor/panthor_sched.c | 18 ++++++++++++++++++
> include/uapi/drm/panthor_drm.h | 9 +++++++++
> 3 files changed, 29 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
> index ac7e53f6e3f0..1498c97b4b85 100644
> --- 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 |
> @@ -1507,7 +1508,7 @@ static const struct drm_driver panthor_drm_driver = {
> .desc = "Panthor DRM driver",
> .date = "20230801",
> .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 ef4bec7ff9c7..97ed5fe5a191 100644
> --- 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 87c9cb555dd1..b99763cbae48 100644
> --- 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,
> };
>
> /**
