From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: emu10k1x/AudigyLS period table Date: Tue, 29 Jun 2004 18:21:55 +0200 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: References: <1e6ff561e6a898.1e6a8981e6ff56@southeast.rr.com> Mime-Version: 1.0 (generated by SEMI 1.14.5 - "Awara-Onsen") Content-Type: text/plain; charset=US-ASCII Return-path: In-Reply-To: <1e6ff561e6a898.1e6a8981e6ff56@southeast.rr.com> Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: fmoraes@nc.rr.com Cc: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org At Mon, 28 Jun 2004 22:49:43 -0400, fmoraes@nc.rr.com wrote: > > This the information that James Courtier-Dutton found about the AudigyLS that also works for the emu10k1x: > > #define PLAYBACK_LIST_ADDR 0x00 /* Base DMA address of a list of pointers to each period/size */ > /* One list entry: 4 bytes for DMA address, > * 4 bytes for period_size << 16. > * One list entry is 8 bytes long. > * One list entry for each period in the buffer. > */ > #define PLAYBACK_LIST_SIZE 0x01 /* Size of list in bytes << 16. E.g. 8 periods -> 0x00380000 */ > #define PLAYBACK_LIST_PTR 0x02 /* Pointer to the current period being played */ > > Is this in anyway similar to the emu10k1 PTB scatter-gather? Just wondering if they reused the design. No, it looks rather similar with the buffer descriptors used in via82xx or intel8x0 to me. You can take a look at via82xx code for supporting SG-buffer. It's a bit complicated because the period size isn't always aligned to the page size. Takashi ------------------------------------------------------- This SF.Net email sponsored by Black Hat Briefings & Training. Attend Black Hat Briefings & Training, Las Vegas July 24-29 - digital self defense, top technical experts, no vendor pitches, unmatched networking opportunities. Visit www.blackhat.com