be2iscsi: Fix soft lockup in mgmt_get_all_if_id path using bmbx
We are taking mbox_lock spinlock which disables pre-emption before we
poll for mbox completion. Waiting there with spinlock held in excess of
20s will cause soft lockup.
Actual fix is to change mbox_lock to mutex. The changes are done in
phases. This is the first part.
1. Changed mgmt_get_all_if_id to use MCC where after posting lock is
released.
2. Changed be_mbox_db_ready_wait to busy wait for 12s max and removed
wait_event_timeout. Added error handling code for IO reads.
OPCODE_COMMON_QUERY_FIRMWARE_CONFIG mbox command takes 8s time when
unreachable boot targets configured.
Signed-off-by: Jitendra Bhivare <jitendra.bhivare@avagotech.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/be2iscsi/be_cmds.c b/drivers/scsi/be2iscsi/be_cmds.c
index 2778089..cd50e3c 100644
--- a/drivers/scsi/be2iscsi/be_cmds.c
+++ b/drivers/scsi/be2iscsi/be_cmds.c
@@ -587,47 +587,42 @@
**/
static int be_mbox_db_ready_wait(struct be_ctrl_info *ctrl)
{
-#define BEISCSI_MBX_RDY_BIT_TIMEOUT 4000 /* 4sec */
+#define BEISCSI_MBX_RDY_BIT_TIMEOUT 12000 /* 12sec */
void __iomem *db = ctrl->db + MPU_MAILBOX_DB_OFFSET;
struct beiscsi_hba *phba = pci_get_drvdata(ctrl->pdev);
unsigned long timeout;
- bool read_flag = false;
- int ret = 0, i;
u32 ready;
- DECLARE_WAIT_QUEUE_HEAD_ONSTACK(rdybit_check_q);
- if (beiscsi_error(phba))
- return -EIO;
-
- timeout = jiffies + (HZ * 110);
-
+ /*
+ * This BMBX busy wait path is used during init only.
+ * For the commands executed during init, 5s should suffice.
+ */
+ timeout = jiffies + msecs_to_jiffies(BEISCSI_MBX_RDY_BIT_TIMEOUT);
do {
- for (i = 0; i < BEISCSI_MBX_RDY_BIT_TIMEOUT; i++) {
- ready = ioread32(db) & MPU_MAILBOX_DB_RDY_MASK;
- if (ready) {
- read_flag = true;
- break;
- }
- mdelay(1);
- }
+ if (beiscsi_error(phba))
+ return -EIO;
- if (!read_flag) {
- wait_event_timeout(rdybit_check_q,
- (read_flag != true),
- HZ * 5);
- }
- } while ((time_before(jiffies, timeout)) && !read_flag);
+ ready = ioread32(db);
+ if (ready == 0xffffffff)
+ return -EIO;
- if (!read_flag) {
- beiscsi_log(phba, KERN_ERR,
- BEISCSI_LOG_CONFIG | BEISCSI_LOG_MBOX,
- "BC_%d : FW Timed Out\n");
- phba->fw_timeout = true;
- beiscsi_ue_detect(phba);
- ret = -EBUSY;
- }
+ ready &= MPU_MAILBOX_DB_RDY_MASK;
+ if (ready)
+ return 0;
- return ret;
+ if (time_after(jiffies, timeout))
+ break;
+ mdelay(1);
+ } while (!ready);
+
+ beiscsi_log(phba, KERN_ERR,
+ BEISCSI_LOG_CONFIG | BEISCSI_LOG_MBOX,
+ "BC_%d : FW Timed Out\n");
+
+ phba->fw_timeout = true;
+ beiscsi_ue_detect(phba);
+
+ return -EBUSY;
}
/*
@@ -674,6 +669,9 @@
if (status)
return status;
+ /* RDY is set; small delay before CQE read. */
+ udelay(1);
+
if (be_mcc_compl_is_new(compl)) {
status = be_mcc_compl_process(ctrl, &mbox->compl);
be_mcc_compl_use(compl);