| Message ID | 1644395927-4138-1-git-send-email-wangqing@vivo.com |
|---|---|
| State | New |
| Headers | show |
| Series | mmc: mtk-sd: use div64_u64() instead of do_div() | expand |
Le 17/02/2022 à 16:39, Ulf Hansson a écrit : > On Wed, 9 Feb 2022 at 09:39, Qing Wang <wangqing@vivo.com> wrote: >> >> 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> > > Applied for next, thanks! This is wrong. See [1]. Wang Qing, you should really warn all the people you have sent such patches. CJ [1]: https://lore.kernel.org/linux-kernel/19b96972-cee7-937f-21ce-c78982ed2048@linaro.org/ > > Kind regards > Uffe > > >> --- >> 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 >> >
On Thu, 17 Feb 2022 at 21:00, Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote: > > Le 17/02/2022 à 16:39, Ulf Hansson a écrit : > > On Wed, 9 Feb 2022 at 09:39, Qing Wang <wangqing@vivo.com> wrote: > >> > >> 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> > > > > Applied for next, thanks! > > > This is wrong. > > See [1]. Thanks for reporting this, I am dropping the patch from my next branch! See more comments below. > > > Wang Qing, you should really warn all the people you have sent such patches. > > CJ > > [1]: > https://lore.kernel.org/linux-kernel/19b96972-cee7-937f-21ce-c78982ed2048@linaro.org/ > > > > > > Kind regards > > Uffe > > > > > >> --- > >> 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); I guess a proper patch would be to convert clk_ns into an u32 instead!? > >> timeout += clks; > >> /* in 1048576 sclk cycle unit */ > >> timeout = DIV_ROUND_UP(timeout, BIT(20)); > >> -- Kind regards Uffe
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));