[patch 16/17] mptbase: reset ioc initiator during PCI resume

[akpm@linux-foundation.org]

From: "Darrick J. Wong" <djwong@us.ibm.com>

It appears that the LSI SAS 1064E chip needs to be reset after a
suspend/resume cycle before the driver attempts further communications with
the chip.  Without this patch, resuming the chip results in this error
message being printed repeatedly and no more disk I/O.

mptbase: ioc0: ERROR - Invalid IOC facts reply, msgLength=0 offsetof=6!

So far it seems to fix suspend/resume on all the MPT Fusion cards I have
(SAS and U320 SCSI) but since I don't know the internals of that chip I
can't say for sure if this is a proper fix.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/message/fusion/mptbase.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff -puN drivers/message/fusion/mptbase.c~mptbase-reset-ioc-initiator-during-pci-resume drivers/message/fusion/mptbase.c
--- a/drivers/message/fusion/mptbase.c~mptbase-reset-ioc-initiator-during-pci-resume
+++ a/drivers/message/fusion/mptbase.c
@@ -1830,6 +1830,12 @@ mpt_resume(struct pci_dev *pdev)
 		(mpt_GetIocState(ioc, 1) >> MPI_IOC_STATE_SHIFT),
 		CHIPREG_READ32(&ioc->chip->Doorbell));
 
+	/* put ioc into READY_STATE */
+	if(SendIocReset(ioc, MPI_FUNCTION_IOC_MESSAGE_UNIT_RESET, CAN_SLEEP)) {
+		printk(MYIOC_s_ERR_FMT
+		"pci-resume:  IOC msg unit reset failed!\n", ioc->name);
+	}
+
 	/* bring ioc to operational state */
 	if ((recovery_state = mpt_do_ioc_recovery(ioc,
 	    MPT_HOSTEVENT_IOC_RECOVER, CAN_SLEEP)) != 0) {
_