From: Ludovic Desroches <ludovic.desroches@atmel.com>
Date: Wed, 6 May 2015 13:16:46 +0000 (+0200)
Subject: mmc: atmel-mci: fix bad variable type for clkdiv
X-Git-Tag: firefly_0821_release~3679^2~405
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a72719d75d8e30203d8624465215072b74be30e7;p=firefly-linux-kernel-4.4.55.git

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@atmel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 84b054b08462..e742761679fa 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -1295,7 +1295,7 @@ 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;
 
 		spin_lock_bh(&host->lock);
 		if (!host->mode_reg) {
@@ -1320,7 +1320,12 @@ 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));