2009/8/3 javier Martin <javier.martin@xxxxxxxxxxxxxxxxx>: > As I described in one of my previous mails, I have been trying to port > an old ASoC driver for kernel 2.6.22 to latest stable 2.6.30 kernel. > I am currently facing a big problem which make some repeated samples > appear with a regular pattern: > - frequency of bad samples = 2 * period_size > - bad samples in audio stream are taken from "buffer_size" samples > back in the original file. > > You can reproduce this with: > aplay -t raw -f S16_LE -r8000 8k16bitpcm.wav > > (http://en.wikipedia.org/wiki/WAV to get this file) > > Here I submit two patches: > - One which adds ssi and dma drivers plus a custom machine driver > (imx27asoc_list.patch). > - Another patch which adds wm8974 codec support taken from ASoC > wm8974-upstream branch (wm8974_list.patch). > > Note that the machine driver attached uses wm8974 codec, thus second > patch is needed. Please, note also that patches are currently quite > dirty, and in an early development state. The purpose of this mail is > not to even consider to include them in any branch right now, but to > gather some help to solve the problem. As soon as I have it solved I > will clean all the stuff and try to prepare it for mainline. > > > > -- > Javier Martin > Vista Silicon S.L. > Universidad de Cantabria > CDTUC - FASE C - Oficina S-345 > Avda de los Castros s/n > 39005- Santander. Cantabria. Spain > +34 942 25 32 60 > www.vista-silicon.com > I was doing some random tests and I have found that using "-M" option in aplay makes it work fine. It seems a problem of performance when not using mmap. I don't know if you have something to comment about this. Thanks. -- Javier Martin Vista Silicon S.L. Universidad de Cantabria CDTUC - FASE C - Oficina S-345 Avda de los Castros s/n 39005- Santander. Cantabria. Spain +34 942 25 32 60 www.vista-silicon.com _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
