From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Delvare Subject: Re: Winbond W83L604G Date: Sat, 9 Jul 2011 09:23:34 +0200 Message-ID: <20110709092334.566e6dcd@endymion.delvare> References: <20110707182315.6e28f62a@endymion.delvare> <21511805.221.1310161730242.JavaMail.root@zmail.rockbochs.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <21511805.221.1310161730242.JavaMail.root-N94c1vXlnCs/q/FG96+aB0EOCMrvLtNR@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Tim Nelson Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org Hi Tim, On Fri, 8 Jul 2011 16:48:50 -0500 (CDT), Tim Nelson wrote: > ----- Original Message ----- > > To test the reliability of the SMBus you could dump the whole register > > map: > > # i2cdump -y -r 0x00-0x22 0 0x19 > > and look for XX's. > > I'm seeing a *lot* of 'XX's present. Here are ten samples: > > root@aaa:~# i2cdump -y -r 0x00-0x22 0 0x19 > No size specified (using byte-data access) > 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef > 00: XX XX XX XX XX XX 00 XX 55 XX XX XX XX ff XX XX XXXXXX.XUXXXX.XX > 10: 3f XX XX XX 00 XX XX XX XX XX ff XX XX XX XX XX ?XXX.XXXXX.XXXXX > 20: 95 92 XX ??X > (...) > > What does this mean? Unstable SMBus? Yes. For whatever reason your SMBus misbehaves severely. Maybe a hardware problem. You should try a few dumps from your other device at 0x4c to confirm that this is a bus-wide issue and not only the W83L604G device. Note that there exists an alternative driver for the I2C bus on SCx200, named scx200_i2c. I seem to remember that it is needed in some cases where the scx200_acb driver doesn't work. Maybe this is your case. -- Jean Delvare http://khali.linux-fr.org/wishlist.html