Hi Mauro, On Sat, 11 Apr 2009 08:09:53 -0300 Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxx> wrote: > > On Fri, 10 Apr 2009 23:11:58 -0700 > Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > On Thu, 9 Apr 2009 16:33:05 +1000 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote: > > > > > I have created today's linux-next tree at > > > git://git.kernel.org/pub/scm/linux/kernel/git/sfr/linux-next.git > > > > It has a link failure with i386 allmodconfig due to missing __divdi3. > > > > It's due to this statement in drivers/media/video/cx88/cx88-dsp.c's > > int_goertzel(): > > > > return (u32)(((s64)s_prev2*s_prev2 + (s64)s_prev*s_prev - > > (s64)coeff*s_prev2*s_prev/32768)/N/N); > > > > that gem will need to be converted to use div64() or similar, please. > > Updated to use do_div(). Thank you. It will be included in next-20090414. Andrew, I have included the patch below in case you need it before then. -- Cheers, Stephen Rothwell sfr@xxxxxxxxxxxxxxxx http://www.canb.auug.org.au/~sfr/ commit ec0a97d2dd33e156283dd04c37d77603cb4dbaf7 Author: Miroslav Sustek <sustmidown@xxxxxxxxxx> Date: Mon Apr 6 20:07:04 2009 -0300 V4L/DVB (11441): cx88-dsp: fixing 64bit math cx88-dsp: fixing 64bit math on 32bit kernels Some gcc versions report the missing of __divdi3 Signed-off-by: Miroslav Sustek <sustmidown@xxxxxxxxxx> [mchehab.redhat.com: CodingStyle fixes] Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> diff --git a/drivers/media/video/cx88/cx88-dsp.c b/drivers/media/video/cx88/cx88-dsp.c index a78286e..3e5eaf3 100644 --- a/drivers/media/video/cx88/cx88-dsp.c +++ b/drivers/media/video/cx88/cx88-dsp.c @@ -22,6 +22,7 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/jiffies.h> +#include <asm/div64.h> #include "cx88.h" #include "cx88-reg.h" @@ -100,13 +101,25 @@ static u32 int_goertzel(s16 x[], u32 N, u32 freq) s32 s_prev2 = 0; s32 coeff = 2*int_cos(freq); u32 i; + + u64 tmp; + u32 divisor; + for (i = 0; i < N; i++) { s32 s = x[i] + ((s64)coeff*s_prev/32768) - s_prev2; s_prev2 = s_prev; s_prev = s; } - return (u32)(((s64)s_prev2*s_prev2 + (s64)s_prev*s_prev - - (s64)coeff*s_prev2*s_prev/32768)/N/N); + + tmp = (s64)s_prev2 * s_prev2 + (s64)s_prev * s_prev - + (s64)coeff * s_prev2 * s_prev / 32768; + + /* XXX: N must be low enough so that N*N fits in s32. + * Else we need two divisions. */ + divisor = N * N; + do_div(tmp, divisor); + + return (u32) tmp; } static u32 freq_magnitude(s16 x[], u32 N, u32 freq) -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
