Messages in this thread | | | Subject | Re: [PATCH 1/2] ALSA: firewire-tascam: Fix infinite loop in snd_tscm_stream_get_rate() | From | Takashi Sakamoto <> | Date | Mon, 15 May 2017 23:07:28 +0900 |
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Hi,
On May 15 2017 17:19, Geert Uytterhoeven wrote: > Obviously the intention was to put a limit on the maximum number of > operations. However, for this to work, the check should be > "&& trials++ < 5", not "|| trials++ < 5". > > Fixes: 35efa5c489de63a9 ("ALSA: firewire-tascam: add streaming functionality") > Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> > --- > Compile-tested only. > > Triggered by a false-positive warning from gcc-4.1.2: > > warning: ‘err’ may be used uninitialized in this function > --- > sound/firewire/tascam/tascam-stream.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > 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.
Please let me keep this patch pending.
Thanks
Takashi Sakamoto
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