[PATCH 4.0 082/148] mmc: atmel-mci: fix bad variable type for clkdiv

Greg Kroah-Hartman
2015-06-03T12:48:08Z

From: Ludovic Desroches <ludovic.desroches@atmel.com>

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>

---
drivers/mmc/host/atmel-mci.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -1304,7 +1304,7 @@ static void atmci_set_ios(struct mmc_hos

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

spin_lock_bh(&host->lock);
if (!host->mode_reg) {
@@ -1328,7 +1328,12 @@ static void atmci_set_ios(struct mmc_hos
/* 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));