From: Simon Farnsworth <simon.farnsworth@onelan.co.uk>
To: Henrik Rydberg <rydberg@bitmath.se>
Cc: linux-input@vger.kernel.org,
Benjamin Tissoires <benjamin.tissoires@gmail.com>,
Benjamin Tissoires <benjamin.tissoires@enac.fr>,
Jiri Kosina <jkosina@suse.cz>
Subject: Re: QUANTA touchscreen controller integrated in HP2310ti no longer recognised (regression in 3.5 and later as compared to 3.3)
Date: Wed, 22 Aug 2012 10:40:48 +0100 [thread overview]
Message-ID: <4162927.yOU3A7SJAr@f17simon> (raw)
In-Reply-To: <2303254.RzNp9y400f@f17simon>
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On Wednesday 22 August 2012 10:00:12 Simon Farnsworth wrote:
> On Tuesday 21 August 2012 21:06:26 Henrik Rydberg wrote:
> > Hi Simon,
> >
> > > We're going through our collection of touch screens, making sure that they all
> > > work with current kernels, and we've found one that doesn't work with today's
> > > Linus master.
> > >
> > > lsusb describes the screen as:
> > > Bus 006 Device 002: ID 0408:3001 Quanta Computer, Inc. Optical Touch Screen
> >
> > What about 0408:3008, does that one work?
> >
> I don't have a sample of 0408:3008 to try.
>
> > > Any ideas on the best way to resolve this regression?
> >
> > What does 'cat /sys/bus/hid/devices/0003:0408:3001.0001/modalias' say?
>
> It's the same whether or not I revert the patch:
>
> # cat /sys/bus/hid/devices/0003:0408:3001.0001/modalias
> hid:b0003g0000v00000408p00003001
>
A look at the code said that the only way this could happen is if
hid_have_special_driver is set for this device, and no special driver claimed
it.
I've confirmed this by setting hid.ignore_special_devices to 1; it then works
unpatched.
The entry in the table is:
{ HID_USB_DEVICE(USB_VENDOR_ID_QUANTA, USB_DEVICE_ID_PIXART_IMAGING_INC_OPTICAL_TOUCH_SCREEN) },
This matches the device I have, and causes the problem behaviour.
It looks like the right thing to do is to audit the hid_have_special_driver
table, and confirm that there is an in-kernel special driver for every device
that has an entry.
--
Simon Farnsworth
Software Engineer
ONELAN Ltd
http://www.onelan.com
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next prev parent reply other threads:[~2012-08-22 9:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1700293.Y8yBuPUG33@f17simon>
2012-08-21 19:06 ` QUANTA touchscreen controller integrated in HP2310ti no longer recognised (regression in 3.5 and later as compared to 3.3) Henrik Rydberg
2012-08-22 9:00 ` Simon Farnsworth
2012-08-22 9:40 ` Simon Farnsworth [this message]
2012-08-22 17:04 ` Henrik Rydberg
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