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Date: Wed, 20 Aug 2008 18:23:53 -0600
From: Scott Long <scottl@samsco.org>
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To: Sean Bruno <sbruno@miralink.com>
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Cc: freebsd-scsi@freebsd.org
Subject: Re: RELENG_6 patch for MPT
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Sean Bruno wrote:
> Hmmm...RELENG_6 looks like it has a locking issue at this time.
> 
> The patch below removes the panic due to dead lock, but I'm not sure
> how safe it is.
> 
> 
> Index: /trunk/src/ankeny/src/FreeBSD_RELENG6/sys/dev/mpt/mpt_user.c
> ===================================================================
> --- /trunk/src/ankeny/src/FreeBSD_RELENG6/sys/dev/mpt/mpt_user.c 
> (revision 5657)
> +++ /trunk/src/ankeny/src/FreeBSD_RELENG6/sys/dev/mpt/mpt_user.c 
> (revision 5761)
> @@ -106,15 +106,13 @@
> mpt_user_attach(struct mpt_softc *mpt)
> {
>     mpt_handler_t handler;
>     int error, unit;
> 
> -    MPT_LOCK(mpt);
>     handler.reply_handler = mpt_user_reply_handler;
>     error = mpt_register_handler(mpt, MPT_HANDLER_REPLY, handler,
>                      &user_handler_id);
> -    MPT_UNLOCK(mpt);
>     if (error != 0) {
>         mpt_prt(mpt, "Unable to register user handler!\n");
>         return (error);
>     }
>     unit = device_get_unit(mpt->dev);
> 

I think this is fine to commit.  I fixed it differently in FreeBSD7,
but there's real locking there and enough differences to make it
hard to directly compare.  Go ahead and check it in, if you want.

Scott