From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Andrey Liakhovets" Subject: Re: [Openchrome-users] via epia boards sound quality Date: Sat, 19 Aug 2006 01:02:09 +0400 Message-ID: Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="_===171065599====cgp.dol.ru===_" Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@lists.sourceforge.net Errors-To: alsa-devel-bounces@lists.sourceforge.net To: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org This is a multi-part MIME message --_===171065599====cgp.dol.ru===_ Content-Type: text/plain; charset="KOI8-R" Content-Transfer-Encoding: quoted-printable This letter is continuation of the thread in Openchrome-users: http://wiki.openchrome.org/pipermail/openchrome-users/2006-May/001193.htm= l http://wiki.openchrome.org/pipermail/openchrome-users/2006-May/001199.htm= l http://wiki.openchrome.org/pipermail/openchrome-users/2006-May/001247.htm= l http://wiki.openchrome.org/pipermail/openchrome-users/2006-July/001456.ht= ml I am sorry for continuing this thread but there is good news. In short, the attached 1-line patch against alsa 1.0.11 solves the proble= m (for our VIA EPIA SP8000). Further details: 1) in our lab, we failed in getting bad sound on a running system, despite a long and intensive heating; 2) we have succeded in reproducing the problem at the system start (with = a probability of about 2/3) with a pre-cooled sound codec chip; 3) we have succeded in reproducing the problem on the system running Linu= x by cutting analog power supply from the codec, cooling the codec a= nd reattaching analog power; 4) on wire, the problem looks like undervoltage of codec analog power (2V or less instead of 5V): meanwhile the codec tries to consume about 200mA (instead of <40mA), and the voltage regulator chip beg= ins (from 100mA) reducing the voltage; 5) analysis of the situation with WinXP shows that the WinXP sound driver= loading brings the codec analog voltage (and sound) to norm, and this stat= e is tolerant to actions described under (3); 6) analysis of the WinXP sound driver loading allowed us to detect that v= ery bit, the set of which normalizes the codec's analog power consumption; 7) a check with Linux has confirmed this. If necessary, I can give more details or upload them on our ftp. Andrey Liakhovets --_===171065599====cgp.dol.ru===_ Content-Type: application/octet-stream Content-Disposition: attachment; filename="alsa-kernel-1.0.11-rover-ac97-vt1617a.patch" Content-Transfer-Encoding: base64 ZGlmZiAtTmF1ciBhL3BjaS9hYzk3L2FjOTdfcGF0Y2guYyBiL3BjaS9hYzk3L2FjOTdfcGF0 Y2guYw0KLS0tIGEvcGNpL2FjOTcvYWM5N19wYXRjaC5jCTIwMDYtMDQtMTIgMDA6NDY6NDcg KzA0MDANCisrKyBiL3BjaS9hYzk3L2FjOTdfcGF0Y2guYwkyMDA2LTA3LTI2IDEwOjE1OjU4 ICswNDAwDQpAQCAtMjc0Miw2ICsyNzQyLDcgQEANCiAgKi8NCiBpbnQgcGF0Y2hfdnQxNjE3 YShzdHJ1Y3Qgc25kX2FjOTcgKiBhYzk3KQ0KIHsNCisJc25kX2FjOTdfd3JpdGVfY2FjaGUo YWM5NywgMHg1YywgMHgyMCk7CS8qIGJyaW5nIGFuYWxvZyBwb3dlciBjb25zdW1wdGlvbiB0 byBub3JtYWwsIGxpa2UgV2luWFAgZHJpdmVyIGZvciBFUElBIFNQICovDQogCWFjOTctPmV4 dF9pZCB8PSBBQzk3X0VJX1NQRElGOwkvKiBmb3JjZSB0aGUgZGV0ZWN0aW9uIG9mIHNwZGlm ICovDQogCWFjOTctPnJhdGVzW0FDOTdfUkFURVNfU1BESUZdID0gU05EUlZfUENNX1JBVEVf NDQxMDAgfCBTTkRSVl9QQ01fUkFURV80ODAwMDsNCiAJcmV0dXJuIDA7DQoNCg0KDQo= --_===171065599====cgp.dol.ru===_ Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 --_===171065599====cgp.dol.ru===_ Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Alsa-devel mailing list Alsa-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-devel --_===171065599====cgp.dol.ru===_--