[alsa-devel] [PATCH] ASoC: nau8810: use 64-bit arithmetic instead of 32-bit
Add suffix ULL to constant 256 in order to give the compiler complete information about the proper arithmetic to use.
Notice that such constant is used in a context that expects an expression of type u64 (64 bits, unsigned) and the following expression is currently being evaluated using 32-bit arithmetic:
256 * fs * 4 * nau8810_mclk_scaler[i] / 10
Addresses-Coverity-ID: 1357595 ("Unintentional integer overflow") Signed-off-by: Gustavo A. R. Silva gustavo@embeddedor.com --- sound/soc/codecs/nau8810.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/soc/codecs/nau8810.c b/sound/soc/codecs/nau8810.c index bfd74b8..e7fd0b2 100644 --- a/sound/soc/codecs/nau8810.c +++ b/sound/soc/codecs/nau8810.c @@ -505,7 +505,7 @@ static int nau88l0_calc_pll(unsigned int pll_in, f2_max = 0; scal_sel = ARRAY_SIZE(nau8810_mclk_scaler); for (i = 0; i < ARRAY_SIZE(nau8810_mclk_scaler); i++) { - f2 = 256 * fs * 4 * nau8810_mclk_scaler[i] / 10; + f2 = 256ULL * fs * 4 * nau8810_mclk_scaler[i] / 10; if (f2 > NAU_PLL_FREQ_MIN && f2 < NAU_PLL_FREQ_MAX && f2_max < f2) { f2_max = f2;
Hi Gustavo,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on asoc/for-next] [also build test ERROR on v4.18-rc3 next-20180706] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Gustavo-A-R-Silva/ASoC-nau8810-use-... base: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next config: m68k-allyesconfig (attached as .config) compiler: m68k-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree GCC_VERSION=7.2.0 make.cross ARCH=m68k
All errors (new ones prefixed by >>):
sound/soc/codecs/nau8810.o: In function `nau8810_set_pll':
nau8810.c:(.text+0x53c): undefined reference to `__udivdi3'
--- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
participants (2)
-
Gustavo A. R. Silva
-
kbuild test robot