[PATCH 4/8] [SCSI] mpt2sas : Update the timing requirements for issuing a Hard Reset as per the MPI spec

[Sreekanth Reddy <Sreekanth.Reddy@lsi.com>]

Updated the mpt2sas driver code that issues hard reset to comply with the timing requirements
mentioned in MPI specifications rev V.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@lsi.com>
---

diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
index ce89b14..fc91a5a 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_base.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
@@ -3920,11 +3920,15 @@ _base_diag_reset(struct MPT2SAS_ADAPTER *ioc, int sleep_flag)
 	writel(host_diagnostic | MPI2_DIAG_RESET_ADAPTER,
 	     &ioc->chip->HostDiagnostic);
 
-	/* don't access any registers for 50 milliseconds */
-	msleep(50);
+	/* This delay allows the chip PCIe hardware time to finish reset tasks*/
+	if (sleep_flag == CAN_SLEEP)
+		msleep(MPI2_HARD_RESET_PCIE_FIRST_READ_DELAY_MICRO_SEC/1000);
+	else
+		mdelay(MPI2_HARD_RESET_PCIE_FIRST_READ_DELAY_MICRO_SEC/1000);
 
-	/* 300 second max wait */
-	for (count = 0; count < 3000000 ; count++) {
+	/* Approximately 300 second max wait */
+	for (count = 0; count < (300000000 /
+	    MPI2_HARD_RESET_PCIE_SECOND_READ_DELAY_MICRO_SEC); count++) {
 
 		host_diagnostic = readl(&ioc->chip->HostDiagnostic);
 
@@ -3933,11 +3937,13 @@ _base_diag_reset(struct MPT2SAS_ADAPTER *ioc, int sleep_flag)
 		if (!(host_diagnostic & MPI2_DIAG_RESET_ADAPTER))
 			break;
 
-		/* wait 100 msec */
+		/* Wait to pass the second read delay window */
 		if (sleep_flag == CAN_SLEEP)
-			msleep(1);
+			msleep(MPI2_HARD_RESET_PCIE_SECOND_READ_DELAY_MICRO_SEC\
+				/1000);
 		else
-			mdelay(1);
+			mdelay(MPI2_HARD_RESET_PCIE_SECOND_READ_DELAY_MICRO_SEC\
+				/1000);
 	}
 
 	if (host_diagnostic & MPI2_DIAG_HCB_MODE) {