At Sun, 23 Nov 2008 14:30:24 +0500, Alexander E. Patrakov wrote: > > Hello, > > I have hit a strange bug. To reproduce: > > 1. Build snd-pcsp.ko. > > 2. alsamixer -c pcsp, set the base frequency to 37286 Hz > > 3. $ speaker-test -r 22050 -P 4 -D plughw:pcsp > > speaker-test 1.0.18 > > Playback device is plughw:pcsp > Stream parameters are 22050Hz, S16_LE, 1 channels > Using 16 octaves of pink noise > Rate set to 22050Hz (requested 22050Hz) > Buffer size range from 37 to 38756 > Period size range from 18 to 19379 > Using max buffer size 38756 > Periods = 4 > was set period_size = 0 > was set buffer_size = 38756 > 0 - Front Left > Floating point exception > > I.e., as you see, period size somehow became 0. While debugging this with printfs, I > noticed that the interval for periods in snd_pcm_hw_param_set_near() starts with 4, > but doesn't include it (i.e., is open). > > Also, I found that snd_interval_refine_first() and snd_interval_refine_last(), when > given an open interval, refine it to something like (n n+1). This is obviously > wrong, as there are no integer points in this interval. Changing i->max++ and > i->min-- there to adjust the value by 2 did eliminate the floating point exception, > but replaced it with "Unable to set nperiods 4 for playback: Invalid argument". So > there must be something else also wrong, but I can't pinpoint it and give you a > ready-made patch :( Thanks for reporting. The problem is that speaker-test examines the parameters before calling snd_pcm_hw_params(). After calling, these are set properly (even with pcsp driver :) The fix is committed now. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
