[PATCH 3.2 101/147] ASoC: adau1373: adau1373_hw_params: Silence overflow warning

From: Ben Hutchings
Date: Mon Nov 06 2017 - 18:34:30 EST


3.2.95-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Tim Gardner <tim.gardner@xxxxxxxxxxxxx>

commit 14a1b8ca172f4cfbc544051a729d85a380447a82 upstream.

ADAU1373_BCLKDIV_SOURCE is defined as BIT(5) which uses UL constants. On
amd64 the result of the ones complement operator is then truncated to
unsigned int according to the prototype of snd_soc_update_bits(). I think
gcc is correctly warning that the upper 32 bits are lost.

sound/soc/codecs/adau1373.c: In function 'adau1373_hw_params':
sound/soc/codecs/adau1373.c:940:3: warning: large integer implicitly truncated to unsigned type [-Woverflow]

gcc version 4.6.3

Add 2 more BCLKDIV mask macros as explained by Lars:

The BCLKDIV has three fields. The bitclock divider (bit 0-1), the samplerate
(bit 2-4) and the source select (bit 5). Here we want to update the bitclock
divider field and the samplerate field. When I wrote the code I was lazy and
used ~ADAU1373_BCLKDIV_SOURCE as the mask, which for this register is
functionally equivalent to ADAU1373_BCLKDIV_SR_MASK | ADAU1373_BCLKDIV_BCLK_MASK.

Signed-off-by: Tim Gardner <tim.gardner@xxxxxxxxxxxxx>
Acked-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
sound/soc/codecs/adau1373.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/sound/soc/codecs/adau1373.c
+++ b/sound/soc/codecs/adau1373.c
@@ -133,6 +133,8 @@ struct adau1373 {
#define ADAU1373_DAI_FORMAT_DSP 0x3

#define ADAU1373_BCLKDIV_SOURCE BIT(5)
+#define ADAU1373_BCLKDIV_SR_MASK (0x07 << 2)
+#define ADAU1373_BCLKDIV_BCLK_MASK 0x03
#define ADAU1373_BCLKDIV_32 0x03
#define ADAU1373_BCLKDIV_64 0x02
#define ADAU1373_BCLKDIV_128 0x01
@@ -937,7 +939,8 @@ static int adau1373_hw_params(struct snd
adau1373_dai->enable_src = (div != 0);

snd_soc_update_bits(codec, ADAU1373_BCLKDIV(dai->id),
- ~ADAU1373_BCLKDIV_SOURCE, (div << 2) | ADAU1373_BCLKDIV_64);
+ ADAU1373_BCLKDIV_SR_MASK | ADAU1373_BCLKDIV_BCLK_MASK,
+ (div << 2) | ADAU1373_BCLKDIV_64);

switch (params_format(params)) {
case SNDRV_PCM_FORMAT_S16_LE: