From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Daughtridge Subject: Re: [PATCH] usbhid: call report_fixup before comparing descriptors Date: Tue, 18 Sep 2012 19:21:09 -0700 Message-ID: <50592C15.8060505@kdau.com> References: <50578272.1020902@kdau.com> <20120918161615.GA1439@polaris.bitmath.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pb0-f46.google.com ([209.85.160.46]:37191 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753224Ab2ISCVO (ORCPT ); Tue, 18 Sep 2012 22:21:14 -0400 Received: by pbbrr13 with SMTP id rr13so1286195pbb.19 for ; Tue, 18 Sep 2012 19:21:13 -0700 (PDT) In-Reply-To: <20120918161615.GA1439@polaris.bitmath.org> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Henrik Rydberg , Sergei Shtylyov Cc: Jiri Kosina , linux-input@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org On 09/18/12 09:16 N.U., Henrik Rydberg wrote: > You can use dev_rdesc here instead. Hi Henrik. Thanks for the tip. I tried comparing rdesc to hid->dev_rdesc without any report_fixup call, but the problem (device nonfunctional with "reset_resume error 1" message) still occurred. Upon looking at hid_open_report, I noticed that it calls report_fixup on dev_rdesc (pointer copied to "start") before it is kmemdup'd to rdesc. For most HID drivers, the report_fixup method directly modifies and returns the passed structure instead of returning a new pointer, so dev_rdesc is also modified. Assuming that dev_rdesc is supposed to be the unmodified data, I moved the report_fixup call in hid_open_report to after the kmemdup. This combination successfully solves the original problem. I'll submit a new patch version presently that addresses both points. On 09/18/12 05:00 N.U., Sergei Shtylyov wrote: > Your patch is whitespace damaged, i.e. has all tabs replaced by spaces. Hi Sergei. Thanks for catching that. The munging problem was supposedly fixed in Thunderbird years ago! I guess I'll just mail the new version from the command line. -Kevin