Hi Frank, On Thursday 17 April 2014 16:26:04 Frank Bormann wrote: > A user-space application, which is being configured with the first mux bus > number, executes i2cget/i2cset commands, specifying the i2c bus number and > expecting them to be incremental from the first number. I won't venture to comment on whether bus numbering has ever been considered to be a kernel ABI, other people should be able to comment on that. Any chance to fix the application to find the bus numbers dynamically ? > On Thu, Apr 17, 2014 at 4:15 PM, Laurent Pinchart wrote: > > On Thursday 17 April 2014 13:54:44 Frank Bormann wrote: > > > Hi Laurent, > > > > > > I have a pca9546 on one of my i2c buses. This will create four mux buses > > > in Linux. One of those mux buses then has a pca9542 connected to it, > > > creating another two mux buses on top of the first ones. > > > > > > The 3.8 kernel, I was initially using enumerated, this as: > > > > > > pca9546: 3, 4, 5, 6 > > > pca9542: 7, 8 > > > > > > However, the new 3.12 kernel, I am using now, has changed that > > > enumeration to: > > > > > > pca9546: 3, 4, 7, 8 > > > pca9542: 5, 6 > > > > > > As you may imagine, the pca9542 is connected to bus 4. Apparently, > > > previously, it would finish the initalization of pca9546 before dealing > > > with the pca9542. Now it seems to do the pca9542 initialization as soon > > > as it sees it on mux bus 4. My application however expects the pca9546 > > > buses to be on incremental bus numbers. > > > > I understand that the bus numbers changed, but you still haven't explain > > *why* you need to have fixed bus numbers. Why do you need to know the bus > > number at all ? -- Regards, Laurent Pinchart -- 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
