[PATCH] mmc: dw_mmc: Fix the DTO timeout overflow calculation for 32-bit systems
From: Evgeniy Didin
Date: Wed Feb 21 2018 - 12:58:01 EST
In commit 9d9491a7da2a ("mmc: dw_mmc: Fix the DTO timeout calculation") have been made
changes which can cause multiply overflow for 32-bit systems. It was caught on arc/hsdk board
when "drto_ms" should be 671, but it was 70 and that caused a flow of stack-traces just copying
file from mmc.
Lets cast this multiply to long long int which prevents overflow.
Signed-off-by: Evgeniy Didin <Evgeniy.Didin@xxxxxxxxxxxx>
CC: Alexey Brodkin <abrodkin@xxxxxxxxxxxx>
CC: Douglas Anderson <dianders@xxxxxxxxxxxx>
CC: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
CC: linux-kernel@xxxxxxxxxxxxxxx
CC: linux-snps-arc@xxxxxxxxxxxxxxxxxxx
---
drivers/mmc/host/dw_mmc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 0aa39975f33b..1a0b9751c67c 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1944,7 +1944,7 @@ static void dw_mci_set_drto(struct dw_mci *host)
drto_div = (mci_readl(host, CLKDIV) & 0xff) * 2;
if (drto_div == 0)
drto_div = 1;
- drto_ms = DIV_ROUND_UP(MSEC_PER_SEC * drto_clks * drto_div,
+ drto_ms = DIV_ROUND_UP((uint64_t)MSEC_PER_SEC * drto_clks * drto_div,
host->bus_hz);
/* add a bit spare time */
--
2.11.0