Date: Wed, 18 Sep 1996 11:18:32 -0700 (PDT) From: nsayer@quack.kfu.com To: FreeBSD-gnats-submit@freebsd.org Subject: kern/1637: mss driver causes feedback (squeal) on some laptops Message-ID: <199609181818.LAA01026@morpheus.kfu.com> Resent-Message-ID: <199609181820.LAA03414@freefall.freebsd.org>
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>Number: 1637 >Category: kern >Synopsis: mss driver causes feedback (squeal) on some laptops >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Sep 18 11:20:06 PDT 1996 >Last-Modified: >Originator: Nick Sayer >Organization: Just me >Release: FreeBSD 2.2-960801-SNAP i386 >Environment: Zenith Z-NoteFlex, possibly others. >Description: Using the audio devices causes feedback howl when mic is left near speaker. This happens even if only audio output is being used. >How-To-Repeat: The built in mic on a Z-NoteFlex is close enough to the speaker that unless headphones are used any audio playback will include a terrible howling. >Fix: The default mixer setting for 'record monitor' is full on instead of full off. This is because the "polarity" setting is wrong. *** ad1848_mixer.h.orig Tue Nov 14 01:58:28 1995 --- ad1848_mixer.h Tue Sep 17 13:23:26 1996 *************** *** 95,101 **** MIX_ENT(SOUND_MIXER_LINE, 18, 1, 0, 5, 19, 1, 0, 5), MIX_ENT(SOUND_MIXER_MIC, 0, 1, 5, 1, 1, 1, 5, 1), MIX_ENT(SOUND_MIXER_CD, 2, 1, 0, 5, 3, 1, 0, 5), ! MIX_ENT(SOUND_MIXER_IMIX, 13, 1, 2, 6, 0, 0, 0, 0), MIX_ENT(SOUND_MIXER_ALTPCM, 0, 0, 0, 0, 0, 0, 0, 0), MIX_ENT(SOUND_MIXER_RECLEV, 0, 0, 0, 0, 0, 0, 0, 0), MIX_ENT(SOUND_MIXER_IGAIN, 0, 0, 0, 4, 1, 0, 0, 4), --- 95,101 ---- MIX_ENT(SOUND_MIXER_LINE, 18, 1, 0, 5, 19, 1, 0, 5), MIX_ENT(SOUND_MIXER_MIC, 0, 1, 5, 1, 1, 1, 5, 1), MIX_ENT(SOUND_MIXER_CD, 2, 1, 0, 5, 3, 1, 0, 5), ! MIX_ENT(SOUND_MIXER_IMIX, 13, 0, 2, 6, 0, 0, 0, 0), MIX_ENT(SOUND_MIXER_ALTPCM, 0, 0, 0, 0, 0, 0, 0, 0), MIX_ENT(SOUND_MIXER_RECLEV, 0, 0, 0, 0, 0, 0, 0, 0), MIX_ENT(SOUND_MIXER_IGAIN, 0, 0, 0, 4, 1, 0, 0, 4), It is unclear whether this problem is an undetected epidemic among mss users under FreeBSD or just another localization issue. Perhaps this patch should have an #ifdef MSS_FIX_HOWL around it? >Audit-Trail: >Unformatted:
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