From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mika Westerberg Subject: Re: [PATCH v2] HID: multitouch: Fetch feature reports on demand for Win8 devices Date: Fri, 9 Oct 2015 11:53:08 +0300 Message-ID: <20151009085308.GT1506@lahna.fi.intel.com> References: <1444221223-33481-1-git-send-email-mika.westerberg@linux.intel.com> <20151007133409.GA25728@mail.corp.redhat.com> <20151007155620.GB118995@ubuntu-hedt> <5615C30A.5060503@synaptics.com> <20151008094057.GN1506@lahna.fi.intel.com> <561713FF.9000406@synaptics.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mga03.intel.com ([134.134.136.65]:59431 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933099AbbJIIxN (ORCPT ); Fri, 9 Oct 2015 04:53:13 -0400 Content-Disposition: inline In-Reply-To: <561713FF.9000406@synaptics.com> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Andrew Duggan Cc: Seth Forshee , Benjamin Tissoires , Jiri Kosina , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org On Thu, Oct 08, 2015 at 06:10:23PM -0700, Andrew Duggan wrote: > No, this touchpad doesn't have HID_QUIRK_NO_INIT_REPORTS set and > usbhid/hid-core.c is calling usbhid_init_reports() which is retrieving > feature 8. But, I did some additional testing and I wasn't able to reproduce > this issue on other systems. The failure occurs on a Dell XPS 13 9343, but > the exact same touchpad and the exact same kernel (I booted both systems off > an external HD to ensure that the kernel and OS are identical) I didn't see > a problem. I also tried a different USB PTP touchpad which didn't have an > issue. Also, I tried returning in mt_get_feature() instead of reading the > report when the report id is 8. When I did that everything worked. > > So as of right now, it looks like a single non production USB PTP touchpad > fails on one particular system. But, all other tests have been successful. > > Let me know if you have any other suggestions for me to test. But, it seems > like this failure might be fairly isolated. Thanks a lot for testing all this. If the failure is limited to a single non-production touchpad then, I suppose we should be fine. As long as there are no such systems out there in the wild. One additional thing we could check in mt_get_feature() is if the device is connected via I2C and only in that case fetch the feature in question. Jiri, Benjamin, what do you think?