[alsa-devel] [PATCH] ASoc: au8540: use 64-bit arithmetic instead of 32-bit

Yang Xiao YangX92 at hotmail.com
Tue Nov 27 07:33:16 CET 2018


From: Young_X <YangX92 at hotmail.com>

    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 * 2 * mclk_src_scaling[i].param

Signed-off-by: Young_X <YangX92 at hotmail.com>
---
 sound/soc/codecs/nau8540.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/soc/codecs/nau8540.c b/sound/soc/codecs/nau8540.c
index e3c8cd1..4dd1a60 100644
--- a/sound/soc/codecs/nau8540.c
+++ b/sound/soc/codecs/nau8540.c
@@ -585,7 +585,7 @@ static int nau8540_calc_fll_param(unsigned int fll_in,
 	fvco_max = 0;
 	fvco_sel = ARRAY_SIZE(mclk_src_scaling);
 	for (i = 0; i < ARRAY_SIZE(mclk_src_scaling); i++) {
-		fvco = 256 * fs * 2 * mclk_src_scaling[i].param;
+		fvco = 256ULL * fs * 2 * mclk_src_scaling[i].param;
 		if (fvco > NAU_FVCO_MIN && fvco < NAU_FVCO_MAX &&
 			fvco_max < fvco) {
 			fvco_max = fvco;
-- 
2.7.4



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