kern/84728: [sound] [patch] ac97 broken mixing capabilities checking

Ariff Abdullah skywizard at MyBSD.org.my
Wed Aug 10 18:10:05 GMT 2005


The following reply was made to PR kern/84728; it has been noted by GNATS.

From: Ariff Abdullah <skywizard at MyBSD.org.my>
To: michaels at sdf.lonestar.org
Cc: FreeBSD-gnats-submit at FreeBSD.org, michaels.maillist at gmail.com
Subject: Re: kern/84728: [sound] [patch] ac97 broken mixing capabilities
 checking
Date: Thu, 11 Aug 2005 02:02:05 +0800

 On Wed, 10 Aug 2005 03:27:15 +0000
 michaels at sdf.lonestar.org wrote:
 > 
 > >Number:         84728
 > >Category:       kern
 > >Synopsis:       [sound] [patch] ac97 broken mixing capabilities checking
 > >Confidential:   no
 > >Severity:       non-critical
 > >Priority:       medium
 > >Responsible:    freebsd-bugs
 > >State:          open
 > >Quarter:        
 > >Keywords:       
 > >Date-Required:
 > >Class:          change-request
 > >Submitter-Id:   current-users
 > >Arrival-Date:   Wed Aug 10 03:30:11 GMT 2005
 > >Closed-Date:
 > >Last-Modified:
 > >Originator:     Michael Seyfert
 > >Release:        FreeBSD 7.0-CURRENT i386
 > >Organization:
 > >Environment:
 > System: FreeBSD icemach.my.domain 7.0-CURRENT i386
 > 
 > >Description:
 > 
 > new sys/dev/sound/pcm/ac97.c introduces some problems with mixer
 > capabilities checking.
 > It does not properly set the "width of control field" for cards with
 > a non-default width. As such the volume control is misaligned ( I can
 > only change the volume from 50% to 100% on my audigy card.)
 > 
 > Also, there's an if statement and for loops that logically don't do
 > anything at all, which has me wondering about the quality of this code.
 > 
 > I think the author (Ariff Abdullah <skywizard at MyBSD.org.my>) should redo it.
 > 
 > >How-To-Repeat:
 > 	Audigy 2 card...
 > 
 > >Fix:
 > 
 > Here's a patch to revert this code to the previous version.
 > 
 > --- sys/dev/sound/pcm/ac97.c	Sun Jul 31 08:28:31 2005
 > +++ /home/michael/work/ac97.c	Tue Aug  9 19:12:01 2005
 > @@ -611,39 +611,15 @@
 >  	for (i = 0; i < 32; i++) {
 >  		k = codec->noext? codec->mix[i].enable : 1;
 >  		if (k && (codec->mix[i].reg > 0)) {
 > -			j = old = ac97_rdcd(codec, codec->mix[i].reg);
 > -			if (!(j & 0x8000)) {
 > -				ac97_wrcd(codec, codec->mix[i].reg, j | 0x8000);
 > -				j = ac97_rdcd(codec, codec->mix[i].reg);
 > -			}
 > -			if ((j & 0x8000)) {
 > -				j = ((1 << 6) - 1) << codec->mix[i].ofs;
 > -				if (codec->mix[i].mute)
 > -					j |= 0x8000;
 > -				ac97_wrcd(codec, codec->mix[i].reg, j);
 > -				j = ac97_rdcd(codec, codec->mix[i].reg) & j;
 > -				j >>= codec->mix[i].ofs;
 > -				if (codec->mix[i].reg == AC97_MIX_TONE &&
 > -						((j & 0x0001) == 0x0000))
 > -					j >>= 1;
 > -				for (k = 0; j != 0; k++)
 > -					j >>= 1;
 > -				for (j = 0; k != 0; j++)
 > -					k >>= 1;
 > -				if (j != 0) {
 > -					codec->mix[i].enable = 1;
 > -#if 0
 > -					codec->mix[i].bits = j;
 > -#endif
 > -				} else
 > -					codec->mix[i].enable = 0;
 > -			} else
 > -				codec->mix[i].enable = 0;
 > +			old = ac97_rdcd(codec, codec->mix[i].reg);
 > +			ac97_wrcd(codec, codec->mix[i].reg, 0x3f);
 > +			j = ac97_rdcd(codec, codec->mix[i].reg);
 >  			ac97_wrcd(codec, codec->mix[i].reg, old);
 > +			codec->mix[i].enable = (j != 0 && j != old)? 1 : 0;
 > +			for (k = 1; j & (1 << k); k++);
 > +			codec->mix[i].bits = j? k - codec->mix[i].ofs : 0;
 >  		}
 > -#if 0
 > -		printf("mixch %d, en=%d, b=%d\n", i, codec->mix[i].enable, codec->mix[i].bits);
 > -#endif
 > +		/* printf("mixch %d, en=%d, b=%d\n", i, codec->mix[i].enable, codec->mix[i].bits); */
 >  	}
 >  
 >  	device_printf(codec->dev, "<%s>\n",
 > >Release-Note:
 > >Audit-Trail:
 > >Unformatted:
 > _______________________________________________
 > freebsd-bugs at freebsd.org mailing list
 > http://lists.freebsd.org/mailman/listinfo/freebsd-bugs
 > To unsubscribe, send any mail to "freebsd-bugs-unsubscribe at freebsd.org"
 
 Please try this patch:
 
 --- sys/dev/sound/pcm/ac97.c.orig	Thu Aug 11 01:50:30 2005
 +++ sys/dev/sound/pcm/ac97.c	Thu Aug 11 01:52:35 2005
 @@ -608,33 +608,40 @@
  	if (codec_patch)
  		codec_patch(codec);
  
 +	/*
 +	 * YES. Do ac97_rdcd()  T W I C E.
 +	 */
  	for (i = 0; i < 32; i++) {
  		k = codec->noext? codec->mix[i].enable : 1;
  		if (k && (codec->mix[i].reg > 0)) {
 +			(void)ac97_rdcd(codec, codec->mix[i].reg);
  			j = old = ac97_rdcd(codec, codec->mix[i].reg);
  			if (!(j & 0x8000)) {
  				ac97_wrcd(codec, codec->mix[i].reg, j | 0x8000);
 +				(void)ac97_rdcd(codec, codec->mix[i].reg);
  				j = ac97_rdcd(codec, codec->mix[i].reg);
  			}
  			if ((j & 0x8000)) {
 -				j = ((1 << 6) - 1) << codec->mix[i].ofs;
 +				j = ((1 << codec->mix[i].bits) - 1) << codec->mix[i].ofs;
  				if (codec->mix[i].mute)
  					j |= 0x8000;
  				ac97_wrcd(codec, codec->mix[i].reg, j);
 -				j = ac97_rdcd(codec, codec->mix[i].reg) & j;
 -				j >>= codec->mix[i].ofs;
 +				(void)ac97_rdcd(codec, codec->mix[i].reg);
 +				k = ac97_rdcd(codec, codec->mix[i].reg) & (j & ~0x8000);
 +				k >>= codec->mix[i].ofs;
  				if (codec->mix[i].reg == AC97_MIX_TONE &&
 -						((j & 0x0001) == 0x0000))
 -					j >>= 1;
 -				for (k = 0; j != 0; k++)
 -					j >>= 1;
 +						((k & 0x0001) == 0x0000))
 +					k >>= 1;
  				for (j = 0; k != 0; j++)
  					k >>= 1;
  				if (j != 0) {
 -					codec->mix[i].enable = 1;
  #if 0
 -					codec->mix[i].bits = j;
 +					device_printf(codec->dev,
 +						"%d: %d -> %d\n",
 +						i, codec->mix[i].bits, j);
  #endif
 +					codec->mix[i].enable = 1;
 +					codec->mix[i].bits = j;
  				} else
  					codec->mix[i].enable = 0;
  			} else
 
 
 --
 
 Ariff Abdullah
 MyBSD
 
 http://www.MyBSD.org.my (IPv6/IPv4)
 http://staff.MyBSD.org.my (IPv6/IPv4)
 http://tomoyo.MyBSD.org.my (IPv6/IPv4)


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