linux-kernel - Re: [PATCH] i2c/mips: Fix error return codes from Sibyte i2c bus driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20100626182915.46ab3ecd@hyperion.delvare>
Date:	Sat, 26 Jun 2010 18:29:15 +0200
From:	Jean Delvare <khali@...ux-fr.org>
To:	"Maciej W. Rozycki" <macro@...ux-mips.org>
Cc:	Guenter Roeck <guenter.roeck@...csson.com>,
	"ben-linux@...ff.org" <ben-linux@...ff.org>,
	"hsweeten@...ionengravers.com" <hsweeten@...ionengravers.com>,
	"linux-i2c@...r.kernel.org" <linux-i2c@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] i2c/mips: Fix error return codes from Sibyte i2c bus 
 driver

On Sat, 26 Jun 2010 17:14:59 +0100 (BST), Maciej W. Rozycki wrote:
> On Tue, 22 Jun 2010, Guenter Roeck wrote:
> 
> > > > @@ -104,7 +104,7 @@ static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr,
> > > >  	if (error & M_SMB_ERROR) {
> > > >  		/* Clear error bit by writing a 1 */
> > > >  		csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS));
> > > > -		return -1;      /* XXXKW better error code? */
> > > > +		return -ENXIO;
> > > >  	}
> > > >  
> > > >  	if (data_bytes == 1)
> > > 
> > > Definitely an improvement. However, returning -ENXIO on all errors
> > > seems wrong. This error value should only be returned on missing ack
> > > from the slave on address byte. Isn't it possible to distinguish
> > > between different error kinds? M_SMB_ERROR_TYPE seems promising, but
> > > one would need to look up the datasheet (which I don't have) to
> > > discover its meaning.
> > > 
> > Makes sense. I'll dig up a copy of the datasheet and see if I can improve it.
> 
>  The M_SMB_ERROR_TYPE bit is cleared if an expected ackonwledgement has 
> not been seen and set if the transfer has failed after 15 retries.  So 
> that's probably ENXIO for the former and EIO for the latter.

Exactly what Guenter did. Good.

-- 
Jean Delvare
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/