| Message ID | 7580645.enu4DmUPIv@wuerfel (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | d1afdf34fc17bd2e1c96dc6196c562fa8906a026 |
| Headers | show |
On 11/20/2015 05:32 PM, Arnd Bergmann wrote: > The new optimized do_div implementation (now in asm-generic/next) exposes a > glitch in the brownstone audio driver by producing a compile-time warning: > > sound/soc/pxa/brownstone.c: In function 'brownstone_wm8994_hw_params': > sound/soc/pxa/brownstone.c:67:85: warning: comparison of distinct pointer types lacks a cast > sound/soc/pxa/brownstone.c:67:10125: warning: right shift count >= width of type [-Wshift-count-overflow] > sound/soc/pxa/brownstone.c:67:10254: warning: passing argument 1 of '__div64_32' from incompatible pointer type [-Wincompatible-pointer-types] > > The driver just divides two plain integer values, so it should not > use do_div to start with, but has apparently done so ever since the > code was first merged. This replaces do_div with a simple division > operator. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > I think this one is harmless, so we only need it in 4.5 to avoid the warning, > but not backported to earlier kernels. > > Found today on ARM allmodconfig > > diff --git a/sound/soc/pxa/brownstone.c b/sound/soc/pxa/brownstone.c > index 6147e86e9b0f..416ea646c3b1 100644 > --- a/sound/soc/pxa/brownstone.c > +++ b/sound/soc/pxa/brownstone.c > @@ -63,8 +63,7 @@ static int brownstone_wm8994_hw_params(struct snd_pcm_substream *substream, > sysclk = params_rate(params) * 512; > sspa_mclk = params_rate(params) * 64; > } > - sspa_div = freq_out; > - do_div(sspa_div, sspa_mclk); > + sspa_div = freq_out / sspa_mclk; > > snd_soc_dai_set_sysclk(cpu_dai, MMP_SSPA_CLK_AUDIO, freq_out, 0); > snd_soc_dai_set_pll(cpu_dai, MMP_SYSCLK, 0, freq_out, sysclk); > Thanks Arnd. Looks sspa_div is not used at all. So we can remove sspa_div as well as do_div. What do you think. Thanks
diff --git a/sound/soc/pxa/brownstone.c b/sound/soc/pxa/brownstone.c index 6147e86e9b0f..416ea646c3b1 100644 --- a/sound/soc/pxa/brownstone.c +++ b/sound/soc/pxa/brownstone.c @@ -63,8 +63,7 @@ static int brownstone_wm8994_hw_params(struct snd_pcm_substream *substream, sysclk = params_rate(params) * 512; sspa_mclk = params_rate(params) * 64; } - sspa_div = freq_out; - do_div(sspa_div, sspa_mclk); + sspa_div = freq_out / sspa_mclk; snd_soc_dai_set_sysclk(cpu_dai, MMP_SSPA_CLK_AUDIO, freq_out, 0); snd_soc_dai_set_pll(cpu_dai, MMP_SYSCLK, 0, freq_out, sysclk);
The new optimized do_div implementation (now in asm-generic/next) exposes a glitch in the brownstone audio driver by producing a compile-time warning: sound/soc/pxa/brownstone.c: In function 'brownstone_wm8994_hw_params': sound/soc/pxa/brownstone.c:67:85: warning: comparison of distinct pointer types lacks a cast sound/soc/pxa/brownstone.c:67:10125: warning: right shift count >= width of type [-Wshift-count-overflow] sound/soc/pxa/brownstone.c:67:10254: warning: passing argument 1 of '__div64_32' from incompatible pointer type [-Wincompatible-pointer-types] The driver just divides two plain integer values, so it should not use do_div to start with, but has apparently done so ever since the code was first merged. This replaces do_div with a simple division operator. Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- I think this one is harmless, so we only need it in 4.5 to avoid the warning, but not backported to earlier kernels. Found today on ARM allmodconfig