ieee1394: sbp2: prevent rare deadlock in shutdown

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / ieee1394 / sbp2.c

diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c
index 3cb6b479b2ef451e97969ed9fc3031fbc53368f1..017259cc34f3a692216f2553e82fae0f8a927ec8 100644 (file)
--- a/drivers/ieee1394/sbp2.c
+++ b/drivers/ieee1394/sbp2.c
@@ -478,7 +478,7 @@ static void sbp2util_notify_fetch_agent(struct scsi_id_instance_data *scsi_id,
         * There is a small window after a bus reset within which the node
         * entry's generation is current but the reconnect wasn't completed.
         */
-       if (atomic_read(&scsi_id->unfinished_reset))
+       if (unlikely(atomic_read(&scsi_id->state) == SBP2LU_STATE_IN_RESET))
                return;
 
        if (hpsb_node_write(scsi_id->ne,
@@ -489,7 +489,7 @@ static void sbp2util_notify_fetch_agent(struct scsi_id_instance_data *scsi_id,
         * Now accept new SCSI commands, unless a bus reset happended during
         * hpsb_node_write.
         */
-       if (!atomic_read(&scsi_id->unfinished_reset))
+       if (likely(atomic_read(&scsi_id->state) != SBP2LU_STATE_IN_RESET))
                scsi_unblock_requests(scsi_id->scsi_host);
 }
 
@@ -756,7 +756,7 @@ static int sbp2_remove(struct device *dev)
                        sbp2scsi_complete_all_commands(scsi_id, DID_NO_CONNECT);
                /* scsi_remove_device() will trigger shutdown functions of SCSI
                 * highlevel drivers which would deadlock if blocked. */
-               atomic_set(&scsi_id->unfinished_reset, 0);
+               atomic_set(&scsi_id->state, SBP2LU_STATE_IN_SHUTDOWN);
                scsi_unblock_requests(scsi_id->scsi_host);
        }
        sdev = scsi_id->sdev;
@@ -811,7 +811,7 @@ static int sbp2_update(struct unit_directory *ud)
        /* Accept new commands unless there was another bus reset in the
         * meantime. */
        if (hpsb_node_entry_valid(scsi_id->ne)) {
-               atomic_set(&scsi_id->unfinished_reset, 0);
+               atomic_set(&scsi_id->state, SBP2LU_STATE_RUNNING);
                scsi_unblock_requests(scsi_id->scsi_host);
        }
        return 0;
@@ -842,7 +842,7 @@ static struct scsi_id_instance_data *sbp2_alloc_device(struct unit_directory *ud
        INIT_LIST_HEAD(&scsi_id->sbp2_command_orb_completed);
        INIT_LIST_HEAD(&scsi_id->scsi_list);
        spin_lock_init(&scsi_id->sbp2_command_orb_lock);
-       atomic_set(&scsi_id->unfinished_reset, 0);
+       atomic_set(&scsi_id->state, SBP2LU_STATE_RUNNING);
        INIT_WORK(&scsi_id->protocol_work, NULL, NULL);
 
        ud->device.driver_data = scsi_id;
@@ -926,13 +926,14 @@ static void sbp2_host_reset(struct hpsb_host *host)
        struct scsi_id_instance_data *scsi_id;
 
        hi = hpsb_get_hostinfo(&sbp2_highlevel, host);
-
-       if (hi) {
-               list_for_each_entry(scsi_id, &hi->scsi_ids, scsi_list) {
-                       atomic_set(&scsi_id->unfinished_reset, 1);
+       if (!hi)
+               return;
+       list_for_each_entry(scsi_id, &hi->scsi_ids, scsi_list)
+               if (likely(atomic_read(&scsi_id->state) !=
+                          SBP2LU_STATE_IN_SHUTDOWN)) {
+                       atomic_set(&scsi_id->state, SBP2LU_STATE_IN_RESET);
                        scsi_block_requests(scsi_id->scsi_host);
                }
-       }
 }
 
 /*