[SCSI] mpt2sas: Update the timing requirements for issuing a Hard Reset

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

[jejb: checpatch fixes]
Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
index c76b18b..8bb1fe9 100644 (file)
--- a/drivers/scsi/mpt2sas/mpt2sas_base.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
@@ -3936,11 +3936,15 @@ _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);
 
@@ -3949,11 +3953,13 @@ _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) {