On Thu, Jul 21, 2022 at 11:39:06AM +0200, Bastien Nocera wrote: > On Mon, 2022-07-18 at 19:29 +0200, José Expósito wrote: > > Hi! > > > > No code yet, just a kind request for comments and hopefully some > > wisdom > > and experience from Nikolai dealing with HUION devices. > > > > HUION keeps reusing the same vendor and product IDs for their > > devices. > > This makes it really difficult to differentiate between devices and > > handle them in the kernel and also in user space. > > > > Reusing IDs could introduce a problem: > > > > If HUION, or other vendor following the same practices, releases a > > new > > tablet with a duplicated product ID, the UCLogic driver would handle > > it. > > The device might work with the existing code or it might fail because > > of > > a new feature or a whole different firmware. > > > > As far as I know, at the moment there is not a mechanism in place to > > avoid this situation. > > I think that it'd be better to ignore those devices in UCLogic and > > let > > the HID generic driver handle them because using HID generic would > > provide a basic user experience while using UCLogic might fail to > > probe > > the tablet. > > > > DIGImend's web already provides a nice list of supported devices: > > http://digimend.github.io/tablets/ > > > > So, I wonder: > > > > - Do you think it makes sense to ignore untested devices? > > - If the answer is yes, do we have a better option than checking the > > device name against an allow-list? It'd be great to hear other > > people's ideas. > > I don't think it makes sense to ignore untested devices, unless you > know for a fact they won't work. > > But if the name is part of detecting the device, it would certainly > make sense to use that as part of the identifier for the device, rather > than just the USB VIP:PID. Agreed, I also think that adding the name to the vendor/product IDs pair would be a better identifier. However, at this point, we don't have that information for all supported tablets, so I guess that we will have to fix new tablets reusing the VIP:PID as they are released. It is unfortunate, but we'll have to deal with it. Thanks a lot for your comments! Jose > You should be able to add the product strings in the .driver_data, and > check them in probe(). > > Cheers
