At Thu, 19 Jul 2007 12:59:32 -0700, Aaron "Caustik" Robinson wrote: > > We have found that the problem exists because, at certain points in time, > the hardware pointer and application pointer overlap. Basically the hardware > is reading from the period buffer which is currently being written to. How > might this be platform specific? Is there any debugging technique you think > may help find the root cause? It sounds unlikely a platform-specific problem but rather a problem of the driver implementation. Note that the hw_ptr and appl_ptr tracked in pcm struct are within 0 and (runtime->boundary_size - 1). It's not within 0 and (buffer_size-1). So, basically it shouldn't overlap unless it goes across the boundary close to long (32bit or more). Takashi > > On 7/10/07, Jaroslav Kysela <perex@xxxxxxx> wrote: > > > > On Tue, 10 Jul 2007, Aaron "Caustik" Robinson wrote: > > > > > This is on an embedded ARM device, with a custom driver. That's > > > interesting. I never thought about the cache angle. Is there any sort of > > > hack I can put to check if that is the problem? > > > > The cache flush method is quite CPU specific, you have to check datasheet. > > But it's only guess and the problem might be somewhere else. I would > > compare samples DMA ring buffer in the user space and kernel space again. > > Also, put a debug lines to dmix plugin to detect where are samples written > > (to which pointer/area in the DMA ring buffer). dmix assumes that playback > > is running forever and tries to mix data in actual ring buffer position. > > > > Jaroslav > > > > ----- > > Jaroslav Kysela <perex@xxxxxxx> > > Linux Kernel Sound Maintainer > > ALSA Project, SUSE Labs > > > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@xxxxxxxxxxxxxxxx > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel > _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
