[RESEND][PATCH][SCSI] mpt2sas: Fix for issue - Unable to boot from the SAS drive connected to HBA

[<sreekanth.reddy@lsi.com>]

Fix for issue - Unable to boot from the SAS drive connected to HBA

This patch checks whether HBA is SAS2008 B0 controller.
if it is a SAS2008 B0 controller then it use IO-APIC interrupt instead of MSIX,
as SAS2008 B0 controller doesn't support MSIX interrupts.

Signed-off-by: Sreekanth Reddy <sreekanth.reddy@lsi.com>
Cc: <stable@kernel.org>
---

diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
index 6102ef2..fd2f4ad 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_base.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
@@ -1207,6 +1207,15 @@ _base_check_enable_msix(struct MPT2SAS_ADAPTER *ioc)
 {
 	int base;
 	u16 message_control;
+	u8 revision;
+
+	/* Check whether controller SAS2008 B0 controller,
+	   if it is a SAS2008 B0 controller use IO-APIC instead of MSIX */
+	pci_read_config_byte(ioc->pdev, PCI_CLASS_REVISION, &revision);
+	if (ioc->pdev->device == MPI2_MFGPAGE_DEVID_SAS2008 &&
+	    revision == 0x01) {
+		return -EINVAL;
+	}
 
 
 	base = pci_find_capability(ioc->pdev, PCI_CAP_ID_MSIX);