From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Leif Rasmussen Date: Tue, 18 Apr 2000 15:00:35 +0000 Subject: Re: Missing 16bit DMA channel Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sound@vger.kernel.org Dave Mielke wrote: > > [quoted lines by Peter Leif Rasmussen on April 18, 2000, at 09:52] > > >I found in my pile of stuff an ESS1868 soundcard, which should be very SB > >compatible > > Check the comments at the top of "/usr/src/linux/drivers/sound/sb_ess.c". They > seem to be saying that the second DMA option is called "dma16", but that it > only specifies a 16-bit DMA if set to 5, and that all other values really refer > to 8-bit DMAs. > Yes, I looked and I found in that file: * Full duplex is enabled by specifying dma16. While the normal dma must * be one of 0, 1 or 3, dma16 can be one of 0, 1, 3 or 5. DMA 5 is a 16 bit * DMA channel, while the others are 8 bit.. As duplex is what I am looking for. This comment (if still valid) seems to indicate that even a second 8bit DMA channel will make the driver work in full duplex, and only if you really need a 16bit DMA channel you can specify that. The documentation doesn't give any indication of this, so thank you for pointing it out. I couldn't yesterday make it work, though, but will try a little harder now knowing that this card probably should work. As ESS is closely wedded to SB why then can't a true SB card, eg. the SB Vibra 16, be made to use the second 8bit DMA channel in duplex mode? Thanks, Peter