Date: Fri, 18 Jul 1997 09:30:57 -0700 From: Amancio Hasty <hasty@rah.star-gate.com> To: Luigi Rizzo <luigi@labinfo.iet.unipi.it> Cc: multimedia@FreeBSD.ORG Subject: Re: sound and dma ... Message-ID: <199707181630.JAA05399@rah.star-gate.com> In-Reply-To: Your message of "Fri, 18 Jul 1997 16:13:17 %2B0200." <199707181413.QAA17750@labinfo.iet.unipi.it>
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No problem;specially, since , the dma subsystem is so complex for just playing audio --- I think is amazing . Hopefully, with PCI things will get better because the complex buffering scheme is really about reducing latency to the sound card. Have fun! Amancio >From The Desk Of Luigi Rizzo : > > Hi, > > The problem with eliminating functionality like is that > > it will render us uncompatible with the linux or with linux > > apps. > > > > SOUND_PCM_SUBDIVIDE is really use for setting the buffer size and > > to provide multiple buffers. > > > > The sound driver generates N number of buffers based upon the size > > of its pool and the the size of a buffer. The intent is eliminate > > clicks. There is also buffering done on sound cards such as the > > right, I was mistaken... at a more careful reading the code seems > to generate a number of sub-buffers as you mention, and the > 'SUBDIVIDE' ioctl is only of use if one wants to force the driver > to split the available buffer space in more pieces than it would > do using the normal heuristics. In this view (and especially, now that > I understand _how_ it works), I can probably keep the current code. > > Note however that my idea was _not_ to kill the ioctl, just make it a > NOP. > > Cheers > Luigi >
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