Hi Dan,

On Mar 31 2017 21:50, Dan Carpenter wrote:

Hello Takashi Sakamoto,

The patch 5992e30034c4: "ALSA: firewire-motu: add support for MOTU 828mk3 (FireWire/Hybrid) as a model with protocol version 3" from Mar 22, 2017, leads to the following static checker warning:

sound/firewire/motu/motu-protocol-v3.c:104 v3_get_clock_source() warn: mask and shift to zero

sound/firewire/motu/motu-protocol-v3.c 90 static int v3_get_clock_source(struct snd_motu *motu, 91 enum snd_motu_clock_source *src) 92 { 93 __be32 reg; 94 u32 data; 95 unsigned int val; 96 int err; 97 98 err = snd_motu_transaction_read(motu, V3_CLOCK_STATUS_OFFSET, &reg, 99 sizeof(reg)); 100 if (err < 0) 101 return err; 102 data = be32_to_cpu(reg); 103 104 val = (data & V3_CLOCK_SOURCE_MASK) >> V3_CLOCK_SOURCE_SHIFT; 0xff >> 8

val is always zero. These are the only places we use V3_CLOCK_SOURCE_MASK and V3_CLOCK_SOURCE_SHIFT so I have no idea what it should be.

105 if (val == 0x00) { 106 *src = SND_MOTU_CLOCK_SOURCE_INTERNAL; 107 } else if (val == 0x01) { 108 *src = SND_MOTU_CLOCK_SOURCE_WORD_ON_BNC; 109 } else if (val == 0x10) { 110 *src = SND_MOTU_CLOCK_SOURCE_SPDIF_ON_COAX; 111 } else if (val == 0x18 || val == 0x19) { 112 err = snd_motu_transaction_read(motu, V3_OPT_IFACE_MODE_OFFSET, 113 &reg, sizeof(reg)); 114 if (err < 0) 115 return err;

Indeed. It's my mistake.

LSB of the register represents current source of clock, thus no need to shift. I'll post fix this weekend.

Thanks

Takashi Sakamoto