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Message-ID: <44fa41b4d69219b89e805d572df486c4dda77f08.camel@linux.ibm.com>
Subject: Re: [PATCH v2 14/15] scsi: ncr53c8xx: replace CCB_MAGIC with bool
 busy
From:   James Bottomley <jejb@linux.ibm.com>
Reply-To: jejb@linux.ibm.com
To:     Ahelenia =?UTF-8?Q?Ziemia=C5=84ska?= 
        <nabijaczleweli@nabijaczleweli.xyz>
Cc:     Jonathan Corbet <corbet@lwn.net>,
        Federico Vaga <federico.vaga@vaga.pv.it>,
        Alex Shi <alexs@kernel.org>,
        Yanteng Si <siyanteng@loongson.cn>,
        Hu Haowen <src.res@email.cn>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        linux-doc-tw-discuss@lists.sourceforge.net,
        linux-scsi@vger.kernel.org
Date:   Fri, 04 Nov 2022 15:57:20 -0400
In-Reply-To: <27cefe163e602f7d5b35ba2e966dccf9109798f9.1667330271.git.nabijaczleweli@nabijaczleweli.xyz>
References: <cover.1667330271.git.nabijaczleweli@nabijaczleweli.xyz>
         <27cefe163e602f7d5b35ba2e966dccf9109798f9.1667330271.git.nabijaczleweli@nabijaczleweli.xyz>
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On Wed, 2022-11-02 at 00:06 +0100, Ahelenia Ziemia=C5=84ska wrote:
[...]
> @@ -4356,7 +4347,7 @@ static int ncr_queue_command (struct ncb *np,
> struct scsi_cmnd *cmd)
>  	*/
> =20
>  	/* activate this job.  */
> -	cp->magic		=3D CCB_MAGIC;
> +	cp->busy		=3D true;
> =20
>  	/*
>  	**	insert next CCBs into start queue.

Are you sure this is just an internal magic number?  The way these old
scripts engines used to work is that the CCB array forms a mailbox and
the card continually scans the mailbox to see if it has any work to do.
These magic values are often a signal to the card that the CCB array
contains a valid entry it hasn't seen and it should work on it, so the
card might be expecting to see this full 32 bit value.

Regards,

James


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