From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Delvare Subject: Re: Winbond W83L604G Date: Mon, 11 Jul 2011 20:29:15 +0200 Message-ID: <20110711202915.5f4cb17a@endymion.delvare> References: <20110709092334.566e6dcd@endymion.delvare> <2607557.175.1310405514456.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: <2607557.175.1310405514456.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 Mon, 11 Jul 2011 12:31:54 -0500 (CDT), Tim Nelson wrote: > ----- Original Message ----- > > 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. > > When attempting a dump of the device at 0x4c, I do *not* get any 'XX' output. What is interesting is that when running 'i2cdetect -y 0', the device at 0x19 shows up only sporadically. It is not present in every run of i2cdetect. This is consistent with the many XX's in the dump: the W83L604G device sometimes doesn't ack its slave address (or fails in some other way.) Did you check the kernel logs for error messages? > The other device at 0x4c shows up every time, and does not contain 'XX' output. Is it safe to assume there is a problem with the Winbond controller? Or, it's usage on this board (hardware problem?) ? I would indeed suspect an incorrect wiring of the W83L604G. You should double check the SCLK, SDAT, VSS and 3VDD connections of the chip. Do you have a second system to test on? This would rule out a hardware sample error. > I attempted to load the scx200_i2c module but I'm greeted with: > > FATAL: Error inserting scx200_i2c (/lib/modules/2.6.26-2-486/kernel/drivers/i2c/busses/scx200_i2c.ko): No such device > > I've tried with and without having the scx200_acb module loaded. > > Thoughts? You would indeed need to unload the scx200_acb driver first, but also to load the scx200_gpio driver and maybe to pass the proper scl and sda module parameters. But anyway, I don't think you have to do this. If the device at 0x4c works fine, it's most probably not a problem with the SMBus controller nor with the scx200_acb driver, so using scx200_i2c instead would most certainly not help. -- Jean Delvare http://khali.linux-fr.org/wishlist.html