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<p class=MsoPlainText><font size=2 color=blue face=Arial><span lang=EN-US
style='font-size:10.5pt;font-family:Arial;color:blue'>Dear Mark,<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=blue face=Arial><span lang=EN-US
style='font-size:10.5pt;font-family:Arial;color:blue'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=blue face=Arial><span lang=EN-US
style='font-size:10.5pt;font-family:Arial;color:blue'>Thanks for your help, and
I think that is a true direction.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=blue face=Arial><span lang=EN-US
style='font-size:10.5pt;font-family:Arial;color:blue'>I will re-check my driver
as soon as I come back to home.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face=Arial><span lang=EN-US
style='font-size:10.5pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=3 color=blue face=宋体><span
lang=EN-US style='font-size:12.0pt;color:blue'>Wan.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=3 color=blue face=宋体><span
lang=EN-US style='font-size:12.0pt;color:blue'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>-----Original Message-----<br>
From: Mark Brown [mailto:broonie@opensource.wolfsonmicro.com] <br>
Sent: 2010</span>Äê<span lang=EN-US>5</span>ÔÂ<span lang=EN-US>10</span>ÈÕ<span
lang=EN-US> 1:52<br>
To: <st1:PersonName w:st="on">Wan ZongShun</st1:PersonName><br>
Cc: <st1:PersonName w:st="on">Vincent Wan</st1:PersonName>;
alsa-devel@alsa-project.org; linux-arm-kernel<br>
Subject: Re: [alsa-devel] about ALC203 linux driver</span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>On Sun, May 09, 2010 at 11:34:28PM +0800, <st1:PersonName
w:st="on">Wan ZongShun</st1:PersonName> wrote:<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>> here, I used the file named ac97.c which is
located in<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>> linux-2.6\sound\soc\codecs.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>> I am sure that it can call the
'\sound\pci\ac97ac97_codec.c' file and<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>> identify the<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>> ALC203 (like the log file shows 'nuc900 AC'97
codec is ALC203',but sometimes<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>> the return value by reading one AC97 register,
which is not same as<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>> the writing value to the<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>> AC97 register, that is not my expected result, but
sometimes they are same.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>> any suggestions?<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>Not all AC97 registers are writable so check that
you're writing to<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>registers that the CODEC supports writing to but in
general you're going<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>to need to debug your controller driver here.
Make sure you're<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>interacting well with any cache the controller has and
that you are<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>properly synchronising with the controller during reads
(which are<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>fairly slow operations on AC97).<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US
style='font-size:9.0pt'>Also make sure that the CODEC is properly clocked.<o:p></o:p></span></font></p>
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