Hello Boris Brezillon,
Commit de8548813824 ("drm/panthor: Add the scheduler logical block")
from Feb 29, 2024 (linux-next), leads to the following Smatch static
checker warning:
drivers/gpu/drm/panthor/panthor_sched.c:1153 csg_slot_sync_state_locked()
error: uninitialized symbol 'new_state'.
drivers/gpu/drm/panthor/panthor_sched.c
1123 static void
1124 csg_slot_sync_state_locked(struct panthor_device *ptdev, u32 csg_id)
1125 {
1126 struct panthor_csg_slot *csg_slot = &ptdev->scheduler->csg_slots[csg_id];
1127 struct panthor_fw_csg_iface *csg_iface;
1128 struct panthor_group *group;
1129 enum panthor_group_state new_state, old_state;
1130
1131 lockdep_assert_held(&ptdev->scheduler->lock);
1132
1133 csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
1134 group = csg_slot->group;
1135
1136 if (!group)
1137 return;
1138
1139 old_state = group->state;
1140 switch (csg_iface->output->ack & CSG_STATE_MASK) {
^^^^^^^^^^^^^^
This mask is 0x7. Should it be 0x3? That would silence the static
checker warning.
1141 case CSG_STATE_START:
1142 case CSG_STATE_RESUME:
1143 new_state = PANTHOR_CS_GROUP_ACTIVE;
1144 break;
1145 case CSG_STATE_TERMINATE:
1146 new_state = PANTHOR_CS_GROUP_TERMINATED;
1147 break;
1148 case CSG_STATE_SUSPEND:
1149 new_state = PANTHOR_CS_GROUP_SUSPENDED;
1150 break;
1151 }
1152
--> 1153 if (old_state == new_state)
1154 return;
1155
1156 if (new_state == PANTHOR_CS_GROUP_SUSPENDED)
1157 csg_slot_sync_queues_state_locked(ptdev, csg_id);
1158
1159 if (old_state == PANTHOR_CS_GROUP_ACTIVE) {
1160 u32 i;
1161
1162 /* Reset the queue slots so we start from a clean
1163 * state when starting/resuming a new group on this
1164 * CSG slot. No wait needed here, and no ringbell
1165 * either, since the CS slot will only be re-used
1166 * on the next CSG start operation.
1167 */
1168 for (i = 0; i < group->queue_count; i++) {
1169 if (group->queues[i])
1170 cs_slot_reset_locked(ptdev, csg_id, i);
1171 }
1172 }
1173
1174 group->state = new_state;
1175 }
regards,
dan carpenter
