Just as a quick side note, Simon's "hack" compiled as a standalone module fixes the issue for me on stock kernel 3.16.0 - keyboard works perfectly now. So device 06CB:2991 has exactly the same broken descriptor and should probably included in any future solution. Many thanks to everyone involved! Best, Florian On 27.02.2015 15:16, Benjamin Tissoires wrote: > [adding Florian to the thread, he is also affected by this] > > On Tue, Feb 17, 2015 at 9:01 PM, Andrew Duggan <aduggan@xxxxxxxxxxxxx> wrote: >> On 02/17/2015 04:30 AM, Jiri Kosina wrote: >>> >>> On Thu, 29 Jan 2015, linux@xxxxxxxxxxxxxxxx wrote: >>> >>>> From: Simon Wörner <mail@xxxxxxxxxxxxxxxx> >>>> >>>> HID: Add driver for acer keybard with broken rdesc >>> >>> Hi Simon, >>> >>> to make sure proper device <-> driver binding is performed, you also have >>> to add device ID to the hid_have_special_driver[] array. >>> > > To the cost of an error in the kernel log, the proper binding will be > done even if if there is no entry in hid_have_special_driver :) > > See Florian's log: > [ 3.153892] hid-generic 0003:06CB:2991.0003: usage index exceeded > [ 3.153896] hid-generic 0003:06CB:2991.0003: item 0 2 2 2 parsing failed > [ 3.153921] hid-generic: probe of 0003:06CB:2991.0003 failed with error -22 > > So hid-generic will fail to bind the device, so normally hid-acer > should bind it, fix the report descriptor and the keyboard should be > working. > > Not very clean, but it should work :) > >> I have been meaning to respond to this patch. Unfortunately, simply adding >> this driver to the hid_have_special_driver[] list will prevent >> hid-multitouch from binding to the touchpad which shares the same vid and >> pid. My suggestion would be to create a new scan_flag for GD_KEYBOARD and to >> add to the code in hid_scan_collection() which scans the GENDESK usages. >> Similar to the code which is searching for HID_GD_POINTER. Then in >> hid_scan_report() we could assign a group for this driver based on the pid >> and the GD_KEYBOARD scan flag in the vendor handling code. > > This could work, but that means that the list of special quirks after > the parsing is going to explode :( > > Plus we have to be sure that the scan_report doesn't fail or we will > not be able to tag the device correctly. > >> >> I can help out with implementing this part of the patch if there aren't any >> other suggestions. Adding a new group and more code to the hid_scan_report() >> vendor handling code is definately not ideal. But, I am not sure of a better >> way of binding different sub drivers to devices with the same vid and pid. >> >> An alternative would be to have hid-rmi handle all Synaptics touchpads, even >> the ones which currently use hid-multitouch. Then the keyboard report >> descriptor fixup could just be handled in hid-rmi. Accessing the finger data >> via rmi mode would also have the benefit of being able to report events >> which are currently not supported by the PTP collection (ie ABS_MT_PRESSURE, >> ABS_MT_TOUCH_MAJOR/MINOR). The touchpads which currently use hid-multitouch >> report finger data a little differently then the ones currently using >> hid-rmi so there is some work which would need to be done to add support for >> them in hid-rmi. >> > > I am not sure we want to do that. Because we don't want hid-rmi to fix > all crappy keyboards around when the OEM reuses the synaptics PID. > > Maybe a better way of handling such situation is to provide a generic > mechanism to overwrite/patch the report descriptor so that we could > get rid of the drivers which just fix the report descriptor. > I have on a branch a version where I look into /lib/firmware/hid if > there is a matching device and a matching report descriptor. Then, I > read this firmware dynamically and patch the report descriptor. > This however requires that the hid modules are not included directly > in the kernel, or the /lib/firmware dir is not available and the > device doesn't bind. > > Cheers, > Benjamin > -- > To unsubscribe from this list: send the line "unsubscribe linux-input" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- SENT FROM MY DEC VT50 TERMINAL
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