diff options
| author | Karen Higgins <karen.higgins@qlogic.com> | 2013-01-20 23:51:00 -0500 |
|---|---|---|
| committer | James Bottomley <JBottomley@Parallels.com> | 2013-01-30 13:47:16 +1100 |
| commit | 5b1c1bff07d579f8a7b672d4e5262d52eba5ef01 (patch) | |
| tree | 83b802ffe3e95af2c8e2ecfc1fc907143149f274 /drivers/scsi/qla4xxx | |
| parent | ff4108dce9e82acbde8e8b1899aaa4d91bf504b7 (diff) | |
[SCSI] qla4xxx: Throttle active IOCBs to firmware limits
Problem:
QLA4xxx firmware may assert if given more IOCBs than it can handle.
Solution:
The driver was updated to throttle the number of active IOCBs based
on the total number of IOCB buffers received from get_firmware_status
mbx_sts[2].
Signed-off-by: Karen Higgins <karen.higgins@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/qla4xxx')
| -rw-r--r-- | drivers/scsi/qla4xxx/ql4_def.h | 2 | ||||
| -rw-r--r-- | drivers/scsi/qla4xxx/ql4_iocb.c | 2 | ||||
| -rw-r--r-- | drivers/scsi/qla4xxx/ql4_mbx.c | 20 |
3 files changed, 21 insertions, 3 deletions
diff --git a/drivers/scsi/qla4xxx/ql4_def.h b/drivers/scsi/qla4xxx/ql4_def.h index 8f419376666..ad580625a47 100644 --- a/drivers/scsi/qla4xxx/ql4_def.h +++ b/drivers/scsi/qla4xxx/ql4_def.h @@ -136,6 +136,7 @@ #define RESPONSE_QUEUE_DEPTH 64 #define QUEUE_SIZE 64 #define DMA_BUFFER_SIZE 512 +#define IOCB_HIWAT_CUSHION 4 /* * Misc @@ -540,6 +541,7 @@ struct scsi_qla_host { uint32_t tot_ddbs; uint16_t iocb_cnt; + uint16_t iocb_hiwat; /* SRB cache. */ #define SRB_MIN_REQ 128 diff --git a/drivers/scsi/qla4xxx/ql4_iocb.c b/drivers/scsi/qla4xxx/ql4_iocb.c index f48f37a281d..14fec976f63 100644 --- a/drivers/scsi/qla4xxx/ql4_iocb.c +++ b/drivers/scsi/qla4xxx/ql4_iocb.c @@ -316,7 +316,7 @@ int qla4xxx_send_command_to_isp(struct scsi_qla_host *ha, struct srb * srb) goto queuing_error; /* total iocbs active */ - if ((ha->iocb_cnt + req_cnt) >= REQUEST_QUEUE_DEPTH) + if ((ha->iocb_cnt + req_cnt) >= ha->iocb_hiwat) goto queuing_error; /* Build command packet */ diff --git a/drivers/scsi/qla4xxx/ql4_mbx.c b/drivers/scsi/qla4xxx/ql4_mbx.c index 1c57c227c80..81e738d61ec 100644 --- a/drivers/scsi/qla4xxx/ql4_mbx.c +++ b/drivers/scsi/qla4xxx/ql4_mbx.c @@ -697,8 +697,24 @@ int qla4xxx_get_firmware_status(struct scsi_qla_host * ha) return QLA_ERROR; } - ql4_printk(KERN_INFO, ha, "%ld firmware IOCBs available (%d).\n", - ha->host_no, mbox_sts[2]); + /* High-water mark of IOCBs */ + ha->iocb_hiwat = mbox_sts[2]; + DEBUG2(ql4_printk(KERN_INFO, ha, + "%s: firmware IOCBs available = %d\n", __func__, + ha->iocb_hiwat)); + + if (ha->iocb_hiwat > IOCB_HIWAT_CUSHION) + ha->iocb_hiwat -= IOCB_HIWAT_CUSHION; + + /* Ideally, we should not enter this code, as the # of firmware + * IOCBs is hard-coded in the firmware. We set a default + * iocb_hiwat here just in case */ + if (ha->iocb_hiwat == 0) { + ha->iocb_hiwat = REQUEST_QUEUE_DEPTH / 4; + DEBUG2(ql4_printk(KERN_WARNING, ha, + "%s: Setting IOCB's to = %d\n", __func__, + ha->iocb_hiwat)); + } return QLA_SUCCESS; } |