From: Qing Wang <wangqing@vivo.com>
To: Chaotian Jing <chaotian.jing@mediatek.com>,
Ulf Hansson <ulf.hansson@linaro.org>,
Matthias Brugger <matthias.bgg@gmail.com>,
linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org
Cc: Wang Qing <wangqing@vivo.com>
Subject: [PATCH] mmc: mtk-sd: use div64_u64() instead of do_div()
Date: Wed, 9 Feb 2022 00:38:47 -0800 [thread overview]
Message-ID: <1644395927-4138-1-git-send-email-wangqing@vivo.com> (raw)
From: Wang Qing <wangqing@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@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
next reply other threads:[~2022-02-09 8:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-09 8:38 Qing Wang [this message]
2022-02-17 15:39 ` [PATCH] mmc: mtk-sd: use div64_u64() instead of do_div() Ulf Hansson
2022-02-17 20:00 ` Christophe JAILLET
2022-02-28 12:03 ` Ulf Hansson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1644395927-4138-1-git-send-email-wangqing@vivo.com \
--to=wangqing@vivo.com \
--cc=chaotian.jing@mediatek.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=linux-mmc@vger.kernel.org \
--cc=matthias.bgg@gmail.com \
--cc=ulf.hansson@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).