From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: emu10k1 latency / capture period Date: Mon, 21 Jun 2004 17:54:53 +0200 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: References: <1087416890.25102.21.camel@debian> <1087704381.805.20.camel@debian> Mime-Version: 1.0 (generated by SEMI 1.14.5 - "Awara-Onsen") Content-Type: text/plain; charset=US-ASCII Return-path: In-Reply-To: Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Lee Revell Cc: Alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org At Mon, 21 Jun 2004 17:35:18 +0200, I wrote: > > At Sun, 20 Jun 2004 00:06:23 -0400, > Lee Revell wrote: > > > > On Wed, 2004-06-16 at 16:14, Lee Revell wrote: > > > Hey, > > > > > > I am having a problem with the emu10k1 driver where I am unable to set > > > the capture period lower than 512. The result is that the lowest > > > achievable input to output latency is in the neighborhood of 40ms. > > > > > > > I think I may have solved this problem. Here is a patch against > > alsa-driver-1.0.5a. > > > > --- alsa-driver-1.0.5a/alsa-kernel/pci/emu10k1/emupcm.c.orig > > 2004-06-19 23:21:09.000000000 -0400 > > +++ alsa-driver-1.0.5a/alsa-kernel/pci/emu10k1/emupcm.c 2004-06-19 > > 23:21:12.000000000 -0400 > > @@ -932,7 +932,7 @@ > > spin_unlock_irqrestore(&emu->reg_lock, flags); > > emu->capture_efx_interrupt = snd_emu10k1_pcm_efx_interrupt; > > emu->pcm_capture_efx_substream = substream; > > - snd_pcm_hw_constraint_list(runtime, 0, > > SNDRV_PCM_HW_PARAM_PERIOD_SIZE, &hw_constraints_capture_period_sizes); > > + // snd_pcm_hw_constraint_list(runtime, 0, > > SNDRV_PCM_HW_PARAM_PERIOD_SIZE, &hw_constraints_capture_period_sizes); > > return 0; > > } > > > > I do not think that the FX8010 capture device is constrained by the > > period size limitations on the standard emu10k1 capture device. > > Right, this constraint is invalid. Well, after checking the code again, I'm not convinced any more... Are you sure that it works without this constraint on half-duplex capture? Takashi ------------------------------------------------------- This SF.Net email is sponsored by The 2004 JavaOne(SM) Conference Learn from the experts at JavaOne(SM), Sun's Worldwide Java Developer Conference, June 28 - July 1 at the Moscone Center in San Francisco, CA REGISTER AND SAVE! http://java.sun.com/javaone/sf Priority Code NWMGYKND