[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>

1 files changed, 13 insertions, 7 deletions

diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
index c76b18bbacb8..8bb1fe96f21e 100644
--- 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) {