Patch "scsi: cxlflash: Improve EEH recovery time" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

scsi: cxlflash: Improve EEH recovery time

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
scsi-cxlflash-improve-eeh-recovery-time.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: "Matthew R. Ochs" <[email protected]>
Date: Fri, 2 Sep 2016 15:40:03 -0500
Subject: scsi: cxlflash: Improve EEH recovery time

From: Matthew R. Ochs <[email protected]>

commit 05dab43230fdc0d14ca885b473a2740fe017ecb1 upstream.

When an EEH occurs during device initialization, the port timeout logic can cause excessive delays as MMIO reads will fail. Depending on where they are experienced, these delays can lead to a prolonged reset, causing an unnecessary triggering of other timeout logic in the SCSI stack or user applications.

To expedite recovery, the port timeout logic is updated to decay the timeout at a much faster rate when in the presence of a likely EEH frozen event.

---
 drivers/scsi/cxlflash/main.c |    4 ++++
 1 file changed, 4 insertions(+)

@@ -996,6 +996,8 @@ static int wait_port_online(__be64 __iom
 	do {
 		msleep(delay_us / 1000);
 		status = readq_be(&fc_regs[FC_MTIP_STATUS / 8]);
+		if (status == U64_MAX)
+			nretry /= 2;
 	} while ((status & FC_MTIP_STATUS_MASK) != FC_MTIP_STATUS_ONLINE &&
 		 nretry--);
 

@@ -1027,6 +1029,8 @@ static int wait_port_offline(__be64 __io
 	do {
 		msleep(delay_us / 1000);
 		status = readq_be(&fc_regs[FC_MTIP_STATUS / 8]);
+		if (status == U64_MAX)
+			nretry /= 2;
 	} while ((status & FC_MTIP_STATUS_MASK) != FC_MTIP_STATUS_OFFLINE &&
 		 nretry--);
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/scsi-cxlflash-fix-to-avoid-eeh-and-host-reset-collisions.patch queue-4.4/scsi-cxlflash-scan-host-only-after-the-port-is-ready-for-i-o.patch queue-4.4/scsi-cxlflash-improve-eeh-recovery-time.patch