On Wed, May 3, 2017 at 7:11 PM, Darren Hart <dvhart@xxxxxxxxxxxxx> wrote: > On Wed, May 03, 2017 at 05:42:02PM +0300, Andy Shevchenko wrote: >> On Wed, May 3, 2017 at 5:36 PM, Ritesh Raj Sarraf <rrs@xxxxxxxxxx> wrote: >> > Resending again, as Google servers are behaving weird lately. >> > >> > On Sun, 2017-04-30 at 15:54 +0300, Andy Shevchenko wrote: >> >> > > the main issue that driver doesn't >> >> > > send SW_TABLET_MODE event through input device. >> >> > >> >> > Well. Yes. That is one part. If SW_TABLET_MODE is done in the driver, much >> >> > better. My patch was simply in line with some of the other drivers (hp-wmi >> >> > and >> >> > thinkpad_acpi) to get it working for Lenovo Yoga series. >> >> >> >> sysfs ABI for drivers that provide input interface is quite strong for >> >> my opinion. It means I'm not totally objecting, but I would accept it >> >> if and only if there is nothing else could be done. >> > >> > The need we have in the user application is for read-only access. >> >> I does not matter at all! You are proposing a part of ABI which will >> be closer to what is "carved in stone". Here is the problem. >> >> So, I'm really trying hard to get avoid such "small things" which >> would make our lives quite hard in long term prospective while fixing >> short-term issues in a good will. >> >> Please, consider to do it better. For now I didn't hear any proof that >> there is no other way to achieve your goal. > > I spent a day with the Lenovo Yoga 2 11 I have available, and have not yet found > a reliable means of detecting the tablet mode (reverse engineering these things > isn't something I'm expert at though). I've reached out to the original author > for some context, but that didn't lead to any revelations as of yet. Okay, I have pushed to testing current version and put on top the separate patch for switching attribute to be RO. (I just realized it might produce a warning since we have defined and not used function.) > Ultimately, this sysfs attribute is no better or worse than others that exist in > our tree. So until we can provide a better solution, we do need to be careful > to not inadvertently favor one laptop driver over another while seeking to avoid > sysfs stable API issues. > > I do think we need to start distinguishing between core kernel userspace > interfaces and leaf node driver sysfs attributes. More flexibility -- more ways to abuse it OTOH :-) -- With Best Regards, Andy Shevchenko
