On Mon, Nov 27, 2017 at 3:42 PM, Alex Hung <alex.hung@xxxxxxxxxxxxx> wrote: > On Sun, Nov 26, 2017 at 2:28 AM, Jason Gerecke <killertofu@xxxxxxxxx> wrote: >> On November 25, 2017 10:23:33 AM PST, Jason Gerecke <killertofu@xxxxxxxxx> wrote: >>>I've just filed a bug [1] about a device which appears to use the >>>"5-button array" that the patch [2] added support for earlier this >>>year. It seems that on this particular device (a Wacom MobileStudio >>>Pro), there is no "HEBC" entry in the ACPI table. Because of this, the >>>kernel does not load support for the "5-button array" that this device >>>seems to use. > > HEBC seems to be the control method that can report 5 button array; > however, I think we can use either one of the below to workaround > this: > > 1. Add a kernel parameter and a quirk (ex. DMI strings). The downside > is the quirk can grow if more systems do not include HEBC > > 2. Check both HEBC & BTNL (ex. the method that enables 5 button > array). Either one enables 5 button array and this fixes current > problems. > > While 2 is preferable, nothing stops future BIOS skips BTNL in the future... > > Any comments? I will create a patch for testing in a few days. Looking for a tables with HEBC and this one I only can tell that I would assume that tables w/o HEBC can guess HEBC returns value for supporting 5-button array. Though to be on the safe side I would rather vote for DMI based quirk > >>>Please let me know what additional information would be helpful to >>>provide. I am able to test kernel patches. >>> >>>[1]: https://bugzilla.kernel.org/show_bug.cgi?id=197991 >>> >>>[2]: https://patchwork.kernel.org/patch/9571353/ >>>Now instead of four in the eights place / >>>you’ve got three, ‘Cause you added one / >>>(That is to say, eight) to the two, / >>>But you can’t take seven from three, / >>>So you look at the sixty-fours.... -- With Best Regards, Andy Shevchenko
