Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) client-ip=23.128.96.34;
From:   Ondrej Zary <linux@zary.sk>
To:     Sergey Shtylyov <s.shtylyov@omp.ru>
Subject: Re: [PATCH 1/4] pata_parport: fix pata_parport_devchk
Date:   Tue, 3 Oct 2023 19:07:45 +0200
User-Agent: KMail/1.9.10
Cc:     Damien Le Moal <damien.lemoal@opensource.wdc.com>,
        Sudip Mukherjee <sudipm.mukherjee@gmail.com>,
        Christoph Hellwig <hch@lst.de>, Tim Waugh <tim@cyberelk.net>,
        linux-parport@lists.infradead.org, linux-ide@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230930191511.24994-1-linux@zary.sk> <20230930191511.24994-2-linux@zary.sk> <d040b3f7-4222-a027-34d0-5cf62aa63605@omp.ru>
In-Reply-To: <d040b3f7-4222-a027-34d0-5cf62aa63605@omp.ru>
MIME-Version: 1.0
Content-Type: Text/Plain;
  charset="utf-8"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <202310031907.45632.linux@zary.sk>
Precedence: bulk

On Monday 02 October 2023 20:43:09 Sergey Shtylyov wrote:
> Hello!
> 
> On 9/30/23 10:15 PM, Ondrej Zary wrote:
> 
> > There's a 'x' missing in 0x55 in pata_parport_devchk(), causing the
> > detection to always fail. Fix it.
> > 
> > Signed-off-by: Ondrej Zary <linux@zary.sk>
> 
>    I think we need a Fixes: tag here...
> 
> > ---
> >  drivers/ata/pata_parport/pata_parport.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/ata/pata_parport/pata_parport.c b/drivers/ata/pata_parport/pata_parport.c
> > index 1af64d435d3c..258d189f42e5 100644
> > --- a/drivers/ata/pata_parport/pata_parport.c
> > +++ b/drivers/ata/pata_parport/pata_parport.c
> > @@ -64,7 +64,7 @@ static bool pata_parport_devchk(struct ata_port *ap, unsigned int device)
> >  	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 0xaa);
> >  	pi->proto->write_regr(pi, 0, ATA_REG_LBAL, 0x55);
> >  
> > -	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 055);
> > +	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 0x55);
> 
>    Oh, Gawd! How did this ever work?! :-/
>    This bug seems to predate the Big PARIDE move...

This code was not present in PARIDE - it's my bug.
The function is a clone of ata_devchk() without direct port access.
It's called only from softreset so nobody notices the breakage until something goes wrong. The CD-865 drive needs a reset to start working.

-- 
Ondrej Zary