diff --git a/sound/firewire/tascam/tascam-stream.c b/sound/firewire/tascam/tascam-stream.c index e852e46ebe6f..ccfa92fbc145 100644 --- a/sound/firewire/tascam/tascam-stream.c +++ b/sound/firewire/tascam/tascam-stream.c @@ -8,20 +8,37 @@ #include #include "tascam.h" +#define CLOCK_STATUS_MASK 0xffff0000 +#define CLOCK_CONFIG_MASK 0x0000ffff + #define CALLBACK_TIMEOUT 500 static int get_clock(struct snd_tscm *tscm, u32 *data) { + int trial = 0; __be32 reg; int err; - err = snd_fw_transaction(tscm->unit, TCODE_READ_QUADLET_REQUEST, - TSCM_ADDR_BASE + TSCM_OFFSET_CLOCK_STATUS, - ®, sizeof(reg), 0); - if (err >= 0) - *data = be32_to_cpu(reg); + while (trial++ < 5) { + err = snd_fw_transaction(tscm->unit, TCODE_READ_QUADLET_REQUEST, + TSCM_ADDR_BASE + TSCM_OFFSET_CLOCK_STATUS, + ®, sizeof(reg), 0); + if (err < 0) + return err; - return err; + *data = be32_to_cpu(reg); + if (*data & CLOCK_STATUS_MASK) + break; + + // In intermediate state after changing clock status. + msleep(50); + } + + // Still in the intermediate state. + if (trial >= 5) + return -EAGAIN; + + return 0; } static int set_clock(struct snd_tscm *tscm, unsigned int rate, @@ -34,7 +51,7 @@ static int set_clock(struct snd_tscm *tscm, unsigned int rate, err = get_clock(tscm, &data); if (err < 0) return err; - data &= 0x0000ffff; + data &= CLOCK_CONFIG_MASK; if (rate > 0) { data &= 0x000000ff; @@ -79,17 +96,14 @@ static int set_clock(struct snd_tscm *tscm, unsigned int rate, int snd_tscm_stream_get_rate(struct snd_tscm *tscm, unsigned int *rate) { - u32 data = 0x0; - unsigned int trials = 0; + u32 data; int err; - while (data == 0x0 || trials++ < 5) { - err = get_clock(tscm, &data); - if (err < 0) - return err; + err = get_clock(tscm, &data); + if (err < 0) + return err; - data = (data & 0xff000000) >> 24; - } + data = (data & 0xff000000) >> 24; /* Check base rate. */ if ((data & 0x0f) == 0x01)