On Wed, Sep 09, 2015 at 10:14:46AM -0300, Emilio López wrote: > On 09/09/15 01:12, Guenter Roeck wrote: > >On 09/08/2015 08:58 PM, Greg KH wrote: > >>On Tue, Sep 08, 2015 at 06:10:16PM -0700, Guenter Roeck wrote: > >>>Hi Emilio, > >>> > >>>On 09/08/2015 05:51 PM, Emilio López wrote: > >>>>Hi Greg & Guenter, > >>>> > >>>[ ... ] > >>>>>>> > >>>>>>>Unless I am missing something, this is not explained anywhere, > >>>>>>>but it is > >>>>>>>not entirely trivial to understand. I think it should be documented. > >>>> > >>>>I agree. I couldn't find any mention of what this int was supposed > >>>>to be by looking at Documentation/ (is_visible is not even mentioned > >>>>:/) or include/linux/sysfs.h. Once we settle on something I'll > >>>>document it before sending a v2. > >>>> > >>>In the include file ? No strong preference, though. > >>> > >>>>By the way, I wrote a quick coccinelle script to match is_visible() > >>>>users which reference the index (included below), and it found > >>>>references to drivers which do not seem to use any binary > >>>>attributes, so I believe changing the index meaning shouldn't be an > >>>>issue. > >>>> > >>>Good. > >>> > >>>>>>I agree, make i the number of the bin attribute and that should solve > >>>>>>this issue. > >>>>>> > >>>>>No, that would conflict with the "normal" use of is_visible for > >>>>>non-binary > >>>>>attributes, and make the index all but useless, since the > >>>>>is_visible function > >>>>>would have to search through all the attributes anyway to figure > >>>>>out which one > >>>>>is being checked. > >>>> > >>>>Yeah, using the same indexes would be somewhat pointless, although > >>>>not many seem to be using it anyway (only 14 files matched). Others > >>>>seem to be comparing the attr* instead. An alternative would be to > >>>>use negative indexes for binary attributes and positive indexes for > >>>>normal attributes. > >>>> > >>>... and I probably wrote or reviewed a significant percentage of > >>>those ;-). > >>> > >>>Using negative numbers for binary attributes is an interesting idea. > >>>Kind of unusual, though. Greg, any thoughts on that ? > >> > >>Ick, no, that's a mess, maybe we just could drop the index alltogether? > >> > > > >No, please don't. Having to manually compare dozens of index pointers > >would be > >even more of a mess. > > So, what about keeping it the way it is in the patch, and documenting it > thoroughly? Otherwise, we could introduce another "is_bin_visible" function > to do this same thing but just on binary attributes, but I'd rather not add > a new function pointer if possible. is_bin_visiable makes sense to me instead of trying to overload the index number in some crazy way. There's no issue with adding another function pointer. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
