[PATCH] mmc: mtk-sd: use div64_u64() instead of do_div()

[Qing Wang]

From: Wang Qing <wangqing at vivo.com>

do_div() does a 64-by-32 division.
When the divisor is u64, do_div() truncates it to 32 bits, this means it
can test non-zero and be truncated to zero for division.

fix do_div.cocci warning:
do_div() does a 64-by-32 division, please consider using div64_u64 instead.

Signed-off-by: Wang Qing <wangqing at vivo.com>
---
 drivers/mmc/host/mtk-sd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 65037e1..777c9a8
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -766,7 +766,7 @@ static u64 msdc_timeout_cal(struct msdc_host *host, u64 ns, u64 clks)
 		clk_ns  = 1000000000ULL;
 		do_div(clk_ns, mmc->actual_clock);
 		timeout = ns + clk_ns - 1;
-		do_div(timeout, clk_ns);
+		div64_u64(timeout, clk_ns);
 		timeout += clks;
 		/* in 1048576 sclk cycle unit */
 		timeout = DIV_ROUND_UP(timeout, BIT(20));
-- 
2.7.4