[3.13.y-ckt stable] Patch "mmc: atmel-mci: fix bad variable type for clkdiv" has been added to staging queue

[Kamal Mostafa]

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

    mmc: atmel-mci: fix bad variable type for clkdiv

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt22.

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

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 2b5b809fc36b6fe3159415758d3a4fd33ffface7 Mon Sep 17 00:00:00 2001
From: Ludovic Desroches <ludovic.desroches at atmel.com>
Date: Wed, 6 May 2015 15:16:46 +0200
Subject: mmc: atmel-mci: fix bad variable type for clkdiv

commit 60c8f783a18feb95ad967c87e9660caf09fb4700 upstream.

clkdiv is declared as an u32 but it can be set to a negative value
causing a huge divisor value. Change its type to int to avoid this case.

Signed-off-by: Ludovic Desroches <ludovic.desroches at atmel.com>
Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/mmc/host/atmel-mci.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 945a31d..01f9751 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -1300,7 +1300,7 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)

 	if (ios->clock) {
 		unsigned int clock_min = ~0U;
-		u32 clkdiv;
+		int clkdiv;

 		clk_prepare(host->mck);
 		unprepare_clk = true;
@@ -1329,7 +1329,12 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 		/* Calculate clock divider */
 		if (host->caps.has_odd_clk_div) {
 			clkdiv = DIV_ROUND_UP(host->bus_hz, clock_min) - 2;
-			if (clkdiv > 511) {
+			if (clkdiv < 0) {
+				dev_warn(&mmc->class_dev,
+					 "clock %u too fast; using %lu\n",
+					 clock_min, host->bus_hz / 2);
+				clkdiv = 0;
+			} else if (clkdiv > 511) {
 				dev_warn(&mmc->class_dev,
 				         "clock %u too slow; using %lu\n",
 				         clock_min, host->bus_hz / (511 + 2));
--
1.9.1