Patch "net: thunderx: Fix OOPs with ethtool --register-dump" 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

net: thunderx: Fix OOPs with ethtool --register-dump

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:
net-thunderx-fix-oops-with-ethtool-register-dump.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: David Daney <[email protected]>
Date: Tue, 16 Aug 2016 13:30:36 -0700
Subject: net: thunderx: Fix OOPs with ethtool --register-dump

From: David Daney <[email protected]>

commit 1423661fed2c40d6d71b5e2e3aa390f85157f9d5 upstream.

The ethtool_ops .get_regs function attempts to read the nonexistent register NIC_QSET_SQ_0_7_CNM_CHG, which produces a "bus error" type OOPs.

Fix by not attempting to read, and removing the definition of, NIC_QSET_SQ_0_7_CNM_CHG. A zero is written into the register dump to keep the layout unchanged.

---
 drivers/net/ethernet/cavium/thunder/nic_reg.h       |    1 -
 drivers/net/ethernet/cavium/thunder/nicvf_ethtool.c |    5 ++++-
 2 files changed, 4 insertions(+), 2 deletions(-)

@@ -170,7 +170,6 @@
 #define   NIC_QSET_SQ_0_7_DOOR			(0x010838)
 #define   NIC_QSET_SQ_0_7_STATUS		(0x010840)
 #define   NIC_QSET_SQ_0_7_DEBUG			(0x010848)
-#define   NIC_QSET_SQ_0_7_CNM_CHG		(0x010860)
 #define   NIC_QSET_SQ_0_7_STAT_0_1		(0x010900)
 
 #define   NIC_QSET_RBDR_0_1_CFG			(0x010C00)

@@ -380,7 +380,10 @@ static void nicvf_get_regs(struct net_de
 		p[i++] = nicvf_queue_reg_read(nic, NIC_QSET_SQ_0_7_DOOR, q);
 		p[i++] = nicvf_queue_reg_read(nic, NIC_QSET_SQ_0_7_STATUS, q);
 		p[i++] = nicvf_queue_reg_read(nic, NIC_QSET_SQ_0_7_DEBUG, q);
-		p[i++] = nicvf_queue_reg_read(nic, NIC_QSET_SQ_0_7_CNM_CHG, q);
+		/* Padding, was NIC_QSET_SQ_0_7_CNM_CHG, which
+		 * produces bus errors when read
+		 */
+		p[i++] = 0;
 		p[i++] = nicvf_queue_reg_read(nic, NIC_QSET_SQ_0_7_STAT_0_1, q);
 		reg_offset = NIC_QSET_SQ_0_7_STAT_0_1 | (1 << 3);
 		p[i++] = nicvf_queue_reg_read(nic, reg_offset, q);

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

queue-4.4/net-thunderx-fix-oops-with-ethtool-register-dump.patch