| Message ID | 20240425084612.703603-1-boris.brezillon@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/panthor: Make sure we handled the unknown group state properly | expand |
On 25/04/2024 09:46, Boris Brezillon wrote: > When we check for state values returned by the FW, we only cover part of > the 0:7 range. Make sure we catch FW inconsistencies by adding a default > to the switch statement, and flagging the group state as unknown in that > case. > > When an unknown state is detected, we trigger a reset, and consider the > group as unusable after that point, to prevent the potential corruption > from creeping in other places if we continue executing stuff on this > context. > > Reported-by: Dan Carpenter <dan.carpenter@linaro.org> > Suggested-by: Steven Price <steven.price@arm.com> > Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com> Thanks for doing this up - I can tick it off my todo list ;) Reviewed-by: Steven Price <steven.price@arm.com> > --- > drivers/gpu/drm/panthor/panthor_sched.c | 37 +++++++++++++++++++++++-- > 1 file changed, 35 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c > index 6de8c0c702cb..fad4678ca4c8 100644 > --- a/drivers/gpu/drm/panthor/panthor_sched.c > +++ b/drivers/gpu/drm/panthor/panthor_sched.c > @@ -490,6 +490,18 @@ enum panthor_group_state { > * Can no longer be scheduled. The only allowed action is a destruction. > */ > PANTHOR_CS_GROUP_TERMINATED, > + > + /** > + * @PANTHOR_CS_GROUP_UNKNOWN_STATE: Group is an unknown state. > + * > + * The FW returned an inconsistent state. The group is flagged unusable > + * and can no longer be scheduled. The only allowed action is a > + * destruction. > + * > + * When that happens, we also schedule a FW reset, to start from a fresh > + * state. > + */ > + PANTHOR_CS_GROUP_UNKNOWN_STATE, > }; > > /** > @@ -1127,6 +1139,7 @@ csg_slot_sync_state_locked(struct panthor_device *ptdev, u32 csg_id) > struct panthor_fw_csg_iface *csg_iface; > struct panthor_group *group; > enum panthor_group_state new_state, old_state; > + u32 csg_state; > > lockdep_assert_held(&ptdev->scheduler->lock); > > @@ -1137,7 +1150,8 @@ csg_slot_sync_state_locked(struct panthor_device *ptdev, u32 csg_id) > return; > > old_state = group->state; > - switch (csg_iface->output->ack & CSG_STATE_MASK) { > + csg_state = csg_iface->output->ack & CSG_STATE_MASK; > + switch (csg_state) { > case CSG_STATE_START: > case CSG_STATE_RESUME: > new_state = PANTHOR_CS_GROUP_ACTIVE; > @@ -1148,11 +1162,28 @@ csg_slot_sync_state_locked(struct panthor_device *ptdev, u32 csg_id) > case CSG_STATE_SUSPEND: > new_state = PANTHOR_CS_GROUP_SUSPENDED; > break; > + default: > + /* The unknown state might be caused by a FW state corruption, > + * which means the group metadata can't be trusted anymore, and > + * the SUSPEND operation might propagate the corruption to the > + * suspend buffers. Flag the group state as unknown to make > + * sure it's unusable after that point. > + */ > + drm_err(&ptdev->base, "Invalid state on CSG %d (state=%d)", > + csg_id, csg_state); > + new_state = PANTHOR_CS_GROUP_UNKNOWN_STATE; > + break; > } > > if (old_state == new_state) > return; > > + /* The unknown state might be caused by a FW issue, reset the FW to > + * take a fresh start. > + */ > + if (new_state == PANTHOR_CS_GROUP_UNKNOWN_STATE) > + panthor_device_schedule_reset(ptdev); > + > if (new_state == PANTHOR_CS_GROUP_SUSPENDED) > csg_slot_sync_queues_state_locked(ptdev, csg_id); > > @@ -1789,6 +1820,7 @@ static bool > group_can_run(struct panthor_group *group) > { > return group->state != PANTHOR_CS_GROUP_TERMINATED && > + group->state != PANTHOR_CS_GROUP_UNKNOWN_STATE && > !group->destroyed && group->fatal_queues == 0 && > !group->timedout; > } > @@ -2563,7 +2595,8 @@ void panthor_sched_suspend(struct panthor_device *ptdev) > > if (csg_slot->group) { > csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, i, > - CSG_STATE_SUSPEND, > + group_can_run(csg_slot->group) ? > + CSG_STATE_SUSPEND : CSG_STATE_TERMINATE, > CSG_STATE_MASK); > } > }
diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c index 6de8c0c702cb..fad4678ca4c8 100644 --- a/drivers/gpu/drm/panthor/panthor_sched.c +++ b/drivers/gpu/drm/panthor/panthor_sched.c @@ -490,6 +490,18 @@ enum panthor_group_state { * Can no longer be scheduled. The only allowed action is a destruction. */ PANTHOR_CS_GROUP_TERMINATED, + + /** + * @PANTHOR_CS_GROUP_UNKNOWN_STATE: Group is an unknown state. + * + * The FW returned an inconsistent state. The group is flagged unusable + * and can no longer be scheduled. The only allowed action is a + * destruction. + * + * When that happens, we also schedule a FW reset, to start from a fresh + * state. + */ + PANTHOR_CS_GROUP_UNKNOWN_STATE, }; /** @@ -1127,6 +1139,7 @@ csg_slot_sync_state_locked(struct panthor_device *ptdev, u32 csg_id) struct panthor_fw_csg_iface *csg_iface; struct panthor_group *group; enum panthor_group_state new_state, old_state; + u32 csg_state; lockdep_assert_held(&ptdev->scheduler->lock); @@ -1137,7 +1150,8 @@ csg_slot_sync_state_locked(struct panthor_device *ptdev, u32 csg_id) return; old_state = group->state; - switch (csg_iface->output->ack & CSG_STATE_MASK) { + csg_state = csg_iface->output->ack & CSG_STATE_MASK; + switch (csg_state) { case CSG_STATE_START: case CSG_STATE_RESUME: new_state = PANTHOR_CS_GROUP_ACTIVE; @@ -1148,11 +1162,28 @@ csg_slot_sync_state_locked(struct panthor_device *ptdev, u32 csg_id) case CSG_STATE_SUSPEND: new_state = PANTHOR_CS_GROUP_SUSPENDED; break; + default: + /* The unknown state might be caused by a FW state corruption, + * which means the group metadata can't be trusted anymore, and + * the SUSPEND operation might propagate the corruption to the + * suspend buffers. Flag the group state as unknown to make + * sure it's unusable after that point. + */ + drm_err(&ptdev->base, "Invalid state on CSG %d (state=%d)", + csg_id, csg_state); + new_state = PANTHOR_CS_GROUP_UNKNOWN_STATE; + break; } if (old_state == new_state) return; + /* The unknown state might be caused by a FW issue, reset the FW to + * take a fresh start. + */ + if (new_state == PANTHOR_CS_GROUP_UNKNOWN_STATE) + panthor_device_schedule_reset(ptdev); + if (new_state == PANTHOR_CS_GROUP_SUSPENDED) csg_slot_sync_queues_state_locked(ptdev, csg_id); @@ -1789,6 +1820,7 @@ static bool group_can_run(struct panthor_group *group) { return group->state != PANTHOR_CS_GROUP_TERMINATED && + group->state != PANTHOR_CS_GROUP_UNKNOWN_STATE && !group->destroyed && group->fatal_queues == 0 && !group->timedout; } @@ -2563,7 +2595,8 @@ void panthor_sched_suspend(struct panthor_device *ptdev) if (csg_slot->group) { csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, i, - CSG_STATE_SUSPEND, + group_can_run(csg_slot->group) ? + CSG_STATE_SUSPEND : CSG_STATE_TERMINATE, CSG_STATE_MASK); } }
When we check for state values returned by the FW, we only cover part of the 0:7 range. Make sure we catch FW inconsistencies by adding a default to the switch statement, and flagging the group state as unknown in that case. When an unknown state is detected, we trigger a reset, and consider the group as unusable after that point, to prevent the potential corruption from creeping in other places if we continue executing stuff on this context. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Suggested-by: Steven Price <steven.price@arm.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com> --- drivers/gpu/drm/panthor/panthor_sched.c | 37 +++++++++++++++++++++++-- 1 file changed, 35 insertions(+), 2 deletions(-)