On Wed, 11 Feb 2009 14:00:29 +0100, Rodolfo Giometti wrote: > On Tue, Feb 10, 2009 at 11:44:38AM +0100, Jean Delvare wrote: > > On Mon, 9 Feb 2009 21:41:08 +0100, Rodolfo Giometti wrote: > > > On Mon, Feb 09, 2009 at 05:17:20PM +0100, Jean Delvare wrote: > > > > On Fri, 6 Feb 2009 16:23:17 +0100, Rodolfo Giometti wrote: > > > > > It could happen that an i2c adapter may lock the bus due due > > > > > > > > Typo: "due due" -> "due to". > > > > > > Ok. > > > > > > > > electrical problems, so the user may recover this stale state by using: > > > > > > > > > > $ echo 1 > /sys/class/i2c-adapter/i2c-0/reset > > > > > > > > What is the intended purpose, debugging? I would certainly hope that > > > > drivers know by themselves when they need a reset. Requiring users to > > > > reset themselves doesn't sound terribly friendly :( > > > > > > Unluckely not all adapter does it by themselfes! At least not PXA > > > one. I'm currently work on adding this new feature. > > > > Well, if you are going to fix the i2c-pxa driver, and it's the only > > driver using the manual reset feature, then do we really need to add > > this feature? > > I don't know about other controllers, I know about PXA one because I'm > currently working on it. :) > > > > > Don't get me wrong, if this feature is still useful then I am fine > > adding it. But OTOH we still have to think twice when doing such core > > changes, because they increase the memory footprint for all systems. > > I agree. Maybe I can add such entry with a conditional #ifdef DEBUG > and setting it off by default? Yes, I would make it conditional upon CONFIG_I2C_DEBUG_BUS, and possibly make it a private attribute of i2c-pxa if no other developers are interested. > > I am curious what other developers think. Me, I never felt the need for > > a manual reset feature. Usually when I have managed to break an I2C > > controller, cycling the driver would fix it, or if not, it was so > > broken that I had to power-cycle the box anyway. > > > > Are there other developers out there who consider the proposed manual > > reset feature a good thing to have? Please speak up. > > However, regarding PXA controller I found a way to automagically reset > it when it locks. I'll send a patchset ASAP. Well, then I'm not sure if we still care about this debugging patch... -- Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
