Patch "e1000e: fix call to do_div() to use u64 arg" has been added to the 3.18-stable tree

Patch "e1000e: fix call to do_div() to use u64 arg" has been added to the 3.18-stable tree

[gregkh]

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

    e1000e: fix call to do_div() to use u64 arg

to the 3.18-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:
     e1000e-fix-call-to-do_div-to-use-u64-arg.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 30544af5483755b11bb5924736e9e0b45ef0644a Mon Sep 17 00:00:00 2001
From: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Date: Sat, 2 May 2015 01:20:04 -0700
Subject: e1000e: fix call to do_div() to use u64 arg

From: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

commit 30544af5483755b11bb5924736e9e0b45ef0644a upstream.

We were using s64 for lat_ns (latency nano-second value) since in
our calculations a negative value could be a resultant.  For negative
values, we then assign lat_ns to be zero, so the value passed to
do_div() was never negative, but do_div() expects the argument type
to be u64, so do a cast to resolve a compile warning seen on
PowerPC.

CC: Yanjiang Jin <yanjiang.jin@windriver.com>
CC: Yanir Lubetkin <yanirx.lubetkin@intel.com>
Reported-by: Yanjiang Jin <yanjiang.jin@windriver.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/net/ethernet/intel/e1000e/ich8lan.c |   13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

--- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
@@ -983,7 +983,7 @@ static s32 e1000_platform_pm_pch_lpt(str
 		u16 max_snoop, max_nosnoop;
 		u16 max_ltr_enc;	/* max LTR latency encoded */
 		s64 lat_ns;	/* latency (ns) */
-		s64 value;
+		u64 value;
 		u32 rxa;
 
 		if (!hw->adapter->max_frame_size) {
@@ -1010,12 +1010,13 @@ static s32 e1000_platform_pm_pch_lpt(str
 		 */
 		lat_ns = ((s64)rxa * 1024 -
 			  (2 * (s64)hw->adapter->max_frame_size)) * 8 * 1000;
-		if (lat_ns < 0)
-			lat_ns = 0;
-		else
-			do_div(lat_ns, speed);
+		if (lat_ns < 0) {
+			value = 0;
+		} else {
+			value = lat_ns;
+			do_div(value, speed);
+		}
 
-		value = lat_ns;
 		while (value > PCI_LTR_VALUE_MASK) {
 			scale++;
 			value = DIV_ROUND_UP(value, (1 << 5));


Patches currently in stable-queue which might be from jeffrey.t.kirsher@intel.com are

queue-3.18/e1000e-fix-call-to-do_div-to-use-u64-arg.patch