On Wed, Nov 29, 2017 at 7:06 AM, Alex Hung <alex.hung@xxxxxxxxxxxxx> wrote: > On Wed, Nov 29, 2017 at 3:50 AM, <Mario.Limonciello@xxxxxxxx> wrote: >>> -----Original Message----- >>> From: platform-driver-x86-owner@xxxxxxxxxxxxxxx [mailto:platform-driver-x86- >>> owner@xxxxxxxxxxxxxxx] On Behalf Of Andy Shevchenko >>> Sent: Tuesday, November 28, 2017 1:28 PM >>> To: Alex Hung <alex.hung@xxxxxxxxxxxxx> >>> Cc: Jason Gerecke <killertofu@xxxxxxxxx>; platform-driver-x86@xxxxxxxxxxxxxxx; >>> Michal Kepien <kernel@xxxxxxxxxx> >>> Subject: Re: Intel "5-button array" support on MobileStudio Pro >>> >>> 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 > > After thinking through again I think staying safe with DMI quirk may > be a good idea. > > 1. Only one system needs workaround now > 2. Future systems may behave differently and we will have more test samples > > Jason, > Please upload output of dmidecode to > https://bugzilla.kernel.org/show_bug.cgi?id=197991 and I can modify > intel-hid accordingly. > > This may take couple days before I can find a system to test. > File has been uploaded. Thanks to all for looking into this :) Jason --- 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.... >> >> Andy, >> >> Could you provide any insight how this possibly works on Windows? >> I would expect that corner cases like this should completely fall over >> on Windows since it's an Intel driver and not customized per >> OEM or anything. >> >> Maybe would it be possible for the folks at Intel >> who worked on the Windows driver to share information about anything >> different they're doing with regards to something like a possibly missing >> HEBC? It would be good to do the same rather than bandage on a bunch >> of things tied to DMI quirks. If it's not possible to obtain that information, >> then I would agree DMI quirks makes sense though. > > If we can refer how it is done in Windows we can improve it but let's > try DMI quirk first. > >> >> Thanks, >> >>> >>> > >>> >>>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 > > > > -- > Cheers, > Alex Hung
