From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Request for tests: scatter-gather dma support on via686 and emu10k1 Date: Fri, 19 Jul 2002 19:19:50 +0200 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: Mime-Version: 1.0 (generated by SEMI 1.14.3 - "Ushinoya") Content-Type: text/plain; charset=US-ASCII Return-path: Errors-To: alsa-devel-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: alsa-devel@lists.sourceforge.net Cc: alsa-user@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org Hi, i just added the support of scatter-gather (sg) dma support on some chips. some chips such like via686 and emu10k1 have sg dma function, which enables to use discontiguous pages as buffer. hence we'll have almost no memory allocation problem on these chips. on via686 and emu10k1, the playback (and capture for via686) buffers are no longer preallocated but allocated always dynamically (preallocation doesn't make sense for sg buffers). on via686 driver, there is a new constraint. the period byte size must be in power of two, to make sure that the period is aligned to the kernel page size. i don't believe that this matters, though. there are some other chips with this function, via8233, intel8x0 and trident. they will be supported eventually soon. (the porting must be easy but i have no hardware :) anyway, if you have an emu10k1 or via686 soundchip, please test the latest cvs version of alsa-kernel/alsa-driver. thanks, Takashi ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf