[4.2.y-ckt stable] Patch "x86 EDAC, sb_edac.c: Repair damage introduced when "fixing" channel address" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    x86 EDAC, sb_edac.c: Repair damage introduced when "fixing" channel address

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt9.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 6afcdde13712d356a2d5ca8727c1d3c0e8944f30 Mon Sep 17 00:00:00 2001
From: Tony Luck <tony.luck at intel.com>
Date: Thu, 14 Apr 2016 10:21:52 -0700
Subject: x86 EDAC, sb_edac.c: Repair damage introduced when "fixing" channel
 address

commit ff15e95c82768d589957dbb17d7eb7dba7904659 upstream.

In commit:

  eb1af3b71f9d ("Fix computation of channel address")

I switched the "sck_way" variable from holding the log2 value read
from the h/w to instead be the actual number. Unfortunately it
is needed in log2 form when used to shift the address.

Tested-by: Patrick Geary <patrickg at supermicro.com>
Signed-off-by: Tony Luck <tony.luck at intel.com>
Acked-by: Mauro Carvalho Chehab <mchehab at osg.samsung.com>
Cc: Aristeu Rozanski <arozansk at redhat.com>
Cc: Borislav Petkov <bp at alien8.de>
Cc: Linus Torvalds <torvalds at linux-foundation.org>
Cc: Peter Zijlstra <peterz at infradead.org>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: linux-edac at vger.kernel.org
Fixes: eb1af3b71f9d ("Fix computation of channel address")
Signed-off-by: Ingo Molnar <mingo at kernel.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/edac/sb_edac.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c
index 9c61607..fa3460b 100644
--- a/drivers/edac/sb_edac.c
+++ b/drivers/edac/sb_edac.c
@@ -1356,7 +1356,7 @@ static int get_memory_error_data(struct mem_ctl_info *mci,
 	}

 	ch_way = TAD_CH(reg) + 1;
-	sck_way = 1 << TAD_SOCK(reg);
+	sck_way = TAD_SOCK(reg);

 	if (ch_way == 3)
 		idx = addr >> 6;
@@ -1395,7 +1395,7 @@ static int get_memory_error_data(struct mem_ctl_info *mci,
 		switch(ch_way) {
 		case 2:
 		case 4:
-			sck_xch = 1 << sck_way * (ch_way >> 1);
+			sck_xch = (1 << sck_way) * (ch_way >> 1);
 			break;
 		default:
 			sprintf(msg, "Invalid mirror set. Can't decode addr");
@@ -1431,7 +1431,7 @@ static int get_memory_error_data(struct mem_ctl_info *mci,

 	ch_addr = addr - offset;
 	ch_addr >>= (6 + shiftup);
-	ch_addr /= ch_way * sck_way;
+	ch_addr /= sck_xch;
 	ch_addr <<= (6 + shiftup);
 	ch_addr |= addr & ((1 << (6 + shiftup)) - 1);

--
2.7.4