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

From: Qing Wang
Date: Wed Feb 09 2022 - 03:40:33 EST


From: Wang Qing <wangqing@xxxxxxxx>

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@xxxxxxxx>
---
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