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Date: Mon, 22 Oct 2018 12:51:31 +0300
From: Konstantin Belousov <kostikbel@gmail.com>
To: Hans Petter Selasky <hselasky@FreeBSD.org>
Cc: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: Re: svn commit: r339582 - head/sys/dev/sound/midi
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On Mon, Oct 22, 2018 at 08:58:28AM +0000, Hans Petter Selasky wrote:
> Author: hselasky
> Date: Mon Oct 22 08:58:27 2018
> New Revision: 339582
> URL: https://svnweb.freebsd.org/changeset/base/339582
> 
> Log:
>   Drop sequencer mutex around uiomove() and make sure we don't move more bytes
>   than is available, else a panic might happen.
And why it is safe to drop the mutex ?
If it is safe to drop, why do you need the mutex at all ?