From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Timofei V. Bondarenko" Subject: [PATCH] cmipci - utilize ADC48K44K bit Date: Wed, 07 Nov 2007 15:08:19 +0300 Message-ID: <4731AAB3.5000209@ipi.ac.ru> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------070904050109070404060204" Return-path: Received: from ipi.ac.ru (blackpeer.ipi.ac.ru [83.149.227.82]) by alsa0.perex.cz (Postfix) with ESMTP id 59A5B2437D for ; Wed, 7 Nov 2007 13:08:21 +0100 (CET) Received: from black.ipi.ac.ru (black.ipi.ac.ru [192.168.1.44]) by ipi.ac.ru (8.14.1/8.14.1) with ESMTP id lA7C8JHY013611 for ; Wed, 7 Nov 2007 15:08:20 +0300 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org This is a multi-part message in MIME format. --------------070904050109070404060204 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Hi. Setting the ADC48K44K greatly improves capture quality at 48k sampling rate. With this bit clear ADC does ZOH interpolation of every 22th sample at 48k. At frequencies higher than 48k there ADC performs a little better with ADC48K44K bit set. At 44.1k ADC performs a little better with this bit clear. At frequencies below 44.1k there is no difference. Regards, Tim. --------------070904050109070404060204 Content-Type: text/x-patch; name="cmi-adc48k.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="cmi-adc48k.patch" Signed-off-by: Timofei Bondarenko --- alsa-driver-hg20071107/alsa-kernel/pci/cmipci.c 2007-11-01 04:00:07.000000000 +0300 +++ alsa-driver/alsa-kernel/pci/cmipci.c 2007-11-07 14:55:05.000000000 +0300 @@ -869,6 +869,13 @@ static int snd_cmipci_pcm_prepare(struct snd_cmipci_write(cm, CM_REG_CHFORMAT, val); //snd_printd("cmipci: chformat = %08x\n", val); + if (!rec->is_dac && cm->chip_version) { + if (runtime->rate > 44100) + snd_cmipci_set_bit(cm, CM_REG_EXT_MISC, CM_ADC48K44K); + else + snd_cmipci_clear_bit(cm, CM_REG_EXT_MISC, CM_ADC48K44K); + } + rec->running = 0; spin_unlock_irq(&cm->reg_lock); --------------070904050109070404060204 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel --------------070904050109070404060204--