scsi: lpfc: cleanup: convert eq_delay to usdelay

Review of the eq coalescing logic showed the code was a bit fragmented.
Sometimes it would save/set via an interrupt max value, while in others it
would do so via a usdelay. There were also two places changing eq delay,
one place that issued mailbox commands, and another that changed via
register writes if supported.

Clean this up by:

 - Standardizing the operation of lpfc_modify_hba_eq_delay() routine so
   that it is always told of a us delay to impose. The routine then chooses
   the best way to set that - via register or via mbx.

 - Rather than two value types stored in eq->q_mode (usdelay if change via
   register, imax if change via mbox) - q_mode always contains usdelay.
   Before any value change, old vs new value is compared and only if
   different is a change done.

 - Revised the dmult calculation. dmult is not set based on overall imax
   divided by hardware queues - instead imax applies to a single cpu and
   the value will be replicated to all cpus.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index 145c08f112a3..22aec1a9b689 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -9336,7 +9336,7 @@ lpfc_sli4_queue_setup(struct lpfc_hba *phba)
 	struct lpfc_sli4_hdw_queue *qp;
 	LPFC_MBOXQ_t *mboxq;
 	int qidx;
-	uint32_t length;
+	uint32_t length, usdelay;
 	int rc = -ENOMEM;
 
 	/* Check for dual-ULP support */
@@ -9643,10 +9643,15 @@ lpfc_sli4_queue_setup(struct lpfc_hba *phba)
 			phba->sli4_hba.dat_rq->queue_id,
 			phba->sli4_hba.els_cq->queue_id);
 
+	if (phba->cfg_fcp_imax)
+		usdelay = LPFC_SEC_TO_USEC / phba->cfg_fcp_imax;
+	else
+		usdelay = 0;
+
 	for (qidx = 0; qidx < phba->cfg_irq_chann;
 	     qidx += LPFC_MAX_EQ_DELAY_EQID_CNT)
 		lpfc_modify_hba_eq_delay(phba, qidx, LPFC_MAX_EQ_DELAY_EQID_CNT,
-					 phba->cfg_fcp_imax);
+					 usdelay);
 
 	if (phba->sli4_hba.cq_max) {
 		kfree(phba->sli4_hba.cq_lookup);