| Message ID | 1637204329-3314-1-git-send-email-yang.lee@linux.alibaba.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [-next,v2] ethernet: renesas: Use div64_ul instead of do_div | expand |
Hi Yang, On Thu, Nov 18, 2021 at 4:13 AM Yang Li <yang.lee@linux.alibaba.com> wrote: > do_div() does a 64-by-32 division. Here the divisor is an > unsigned long which on some platforms is 64 bit wide. So use > div64_ul instead of do_div to avoid a possible truncation. > > Eliminate the following coccicheck warning: > ./drivers/net/ethernet/renesas/ravb_main.c:2492:1-7: WARNING: > do_div() does a 64-by-32 division, please consider using div64_ul instead. > > Reported-by: Abaci Robot <abaci@linux.alibaba.com> > Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Thanks for your patch! > --- a/drivers/net/ethernet/renesas/ravb_main.c > +++ b/drivers/net/ethernet/renesas/ravb_main.c > @@ -2489,7 +2489,7 @@ static int ravb_set_gti(struct net_device *ndev) > return -EINVAL; > > inc = 1000000000ULL << 20; > - do_div(inc, rate); > + inc = div64_ul(inc, rate); > > if (inc < GTI_TIV_MIN || inc > GTI_TIV_MAX) { > dev_err(dev, "gti.tiv increment 0x%llx is outside the range 0x%x - 0x%x\n", Please also replace #include <asm/div64.h> by #include <linux/math64.h> With that added: Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index b4c597f..2b89710 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -2489,7 +2489,7 @@ static int ravb_set_gti(struct net_device *ndev) return -EINVAL; inc = 1000000000ULL << 20; - do_div(inc, rate); + inc = div64_ul(inc, rate); if (inc < GTI_TIV_MIN || inc > GTI_TIV_MAX) { dev_err(dev, "gti.tiv increment 0x%llx is outside the range 0x%x - 0x%x\n",
do_div() does a 64-by-32 division. Here the divisor is an unsigned long which on some platforms is 64 bit wide. So use div64_ul instead of do_div to avoid a possible truncation. Eliminate the following coccicheck warning: ./drivers/net/ethernet/renesas/ravb_main.c:2492:1-7: WARNING: do_div() does a 64-by-32 division, please consider using div64_ul instead. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> --- change in v2: --Fixed warning message drivers/net/ethernet/renesas/ravb_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)