From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Farnsworth 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 Message-ID: <4162927.yOU3A7SJAr@f17simon> References: <1700293.Y8yBuPUG33@f17simon> <20120821190626.GA1260@polaris.bitmath.org> <2303254.RzNp9y400f@f17simon> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart1873465.y5ja55cG0p"; micalg="pgp-sha1"; protocol="application/pgp-signature" Content-Transfer-Encoding: 7Bit Return-path: Received: from claranet-outbound-smtp03.uk.clara.net ([195.8.89.36]:44888 "EHLO claranet-outbound-smtp03.uk.clara.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758775Ab2HVJk6 (ORCPT ); Wed, 22 Aug 2012 05:40:58 -0400 In-Reply-To: <2303254.RzNp9y400f@f17simon> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Henrik Rydberg Cc: linux-input@vger.kernel.org, Benjamin Tissoires , Benjamin Tissoires , Jiri Kosina --nextPart1873465.y5ja55cG0p Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" 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 --nextPart1873465.y5ja55cG0p Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQEcBAABAgAGBQJQNKklAAoJEIKsye9/dtRW60sH/R3OS5Dytch3JC/18fLoWrpI 8TPPOfWywgm3ntatbvPKY72tw/MBhW/W0UewG0TSdxJjcxiIX1XVu43UFhA1/ngZ wXUe4nvDJTAySiJSThnk7NZmFYOqg0RoyaJ6IpZ85ukSJ4mKPEWRdo506uoPFogx M3H2UrgHOaOgB7DaOMjNhoWHEhzlgb6jDj0ptkfKR/8IvJf12kV0b9XGPvf98Mww /+DcpLW4KVXrc3mjeWTzD8PHvvl1ZZ8nlljMq6ebWhxsnNgu6BkzS33Ql6r+9LhJ l0HP14jyLURA86RTAX9ZJVEbBwKw3UR04GEN3Yr6EJIV0/zxjis18YFitW9T7KQ= =UDAB -----END PGP SIGNATURE----- --nextPart1873465.y5ja55cG0p--