On May 15 2017 23:22, Geert Uytterhoeven wrote:
diff --git a/sound/firewire/tascam/tascam-stream.c b/sound/firewire/tascam/tascam-stream.c index f1657a4e0621ef49..e433b92ac6904db5 100644 --- a/sound/firewire/tascam/tascam-stream.c +++ b/sound/firewire/tascam/tascam-stream.c @@ -84,7 +84,7 @@ int snd_tscm_stream_get_rate(struct snd_tscm *tscm, unsigned int *rate) unsigned int trials = 0; int err;
while (data == 0x0 || trials++ < 5) {
while (data == 0x0 && trials++ < 5) { err = get_clock(tscm, &data); if (err < 0) return err;Yep. It looks a bug.
...However, removal of the bug causes issue that the driver fails to start a pair of capture/playback PCM substream when application requests them mostly the same time, like jackd process.
I think I did apply the bug as a makeshift workaround, then forgot itself when developing the driver... I'd like to have a bit time for further investigation, then post my fix in this development period.
Probably you need a small delay in the loop? Why else do you #include <linux/delay.h>? ;-)
I know PDI1394L40 (link layer) has quirks inconvenient to us. Furthermore, the behaviour of on-board FPGAs with unique firmwares are in black boxes to me.
I prefer deliberate approach for this kind of work, reverse engineering.
Regards
Takashi Sakamoto