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