From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Duggan Subject: Re: [PATCH] HID: rmi: Check that a device is a RMI device before calling RMI functions Date: Wed, 18 Oct 2017 10:28:45 -0700 Message-ID: <37d50592-39b6-680f-6d02-1a7daa9a9208@synaptics.com> References: <1508290656-18871-1-git-send-email-aduggan@synaptics.com> <20171018084803.GE24559@mail.corp.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: Received: from mail-bn3nam01on0068.outbound.protection.outlook.com ([104.47.33.68]:56112 "EHLO NAM01-BN3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750829AbdJRR27 (ORCPT ); Wed, 18 Oct 2017 13:28:59 -0400 In-Reply-To: Content-Language: en-US Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Jiri Kosina , Benjamin Tissoires Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Hendrik Langer On 10/18/2017 07:13 AM, Jiri Kosina wrote: > On Wed, 18 Oct 2017, Benjamin Tissoires wrote: > >>> The hid-rmi driver may handle non rmi devices on composite USB devices. >>> Callbacks need to make sure that the current device is a RMI device before >>> calling RMI specific functions. Most callbacks already have this check, but >>> this patch adds checks to the remaining callbacks. >>> >>> Signed-off-by: Andrew Duggan >>> --- >>> This is the patch which hopefully will address the X1 tablet dock freeze: >>> http://www.spinics.net/lists/linux-input/msg53582.html >>> >>> I was not able to test on a composite USB device so I have not tested confirmed >>> this will fix the reported issues. But, based on the description I think it will. >>> I also added a check for rmi_raw_event() since it could be possible that another >>> hid device using one of the same report IDs as an RMI device could result in calling >>> into unitialized RMI functions. It was also the only callbacl left not checking the >>> RMI_DEVICE flag. I wonder if this explains the attach crash. >>> >>> Anyway, I would appriciate it if Hendrik or someone else with the device could test this >>> patch to confirm it fixes the reported behavior. >> Shouldn't rmi_hid_reset() also get the same check? > I think so as well. Since rmi_hid_reset() is only called from with in the RMI4 driver I didn't think that it needed a check. All of the functions set in struct hid_driver should  now check the RMI_DEVICE flag before calling into the RMI4 driver. But, if I am missing something we can add additional checks. Thanks, Andrew >> From what I can see, even if the patch doesn't fix the immediate issue, >> such a patch should definitively go in as those checks are clearly >> missing. > Agreed; however I'd like to get Hendrik's Tested-by: if possible in case > this really fixes the issue, so I am not merging it right away. > > Hendrik, are you by any chance able to test this patch in a reasonable > timeframe please? > > Thanks! >