Manuel Jander wrote: > AFAIK, it seems that when using a scatter gather buffer, not every > period is located inside of a page. ... > The problem is that a DMA transfer can not go accross 2 different pages. > On Aureal hardware, even on contiguous buffers this causes all sort of > odd problems. Each DMA chunk must be on the same page. > ... > That means that i would have to split each period that crosses a page > boundary into 2 DMA chunks, with all the complications involved because > of irregular sizes, offsets... ARghhh!
Yes. Every driver using SG must do this. Look into bt87x.c or via82xx.c for examples. > I could just leave the period size as a power of 2, on that way, a > period would never cross any page boundary, but most ALSA programs are > too picky to accept that kind of restrictions in most cases. Devices like usb and ymfpci have a fixed period size, but their drivers emulate arbitrary period sizes. Regards, Clemens ------------------------------------------------------- SF.Net is sponsored by: Speed Start Your Linux Apps Now. Build and deploy apps & Web services for Linux with a free DVD software kit from IBM. Click Now! http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
