On 27.02.2015 15:28, Florian Echtler wrote:
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.
Okay, i will include it.
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 :)
The other solutions looks like more work and at least some other problems.
So this "best" and preferred solution, or did i got any thing wrong?
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
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Is there any point i missed or we're good to go now? (expect the new
device id)
Greets,
Simon
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