From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932232AbdBHORC (ORCPT ); Wed, 8 Feb 2017 09:17:02 -0500 Received: from mga07.intel.com ([134.134.136.100]:29199 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753874AbdBHOQ6 (ORCPT ); Wed, 8 Feb 2017 09:16:58 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,346,1477983600"; d="scan'208";a="222817799" Subject: Re: [PATCH v2 1/1] xhci: add USB2 test mode support To: Alexander Stein , Mathias Nyman , Greg Kroah-Hartman References: <20170208134444.18369-1-alexander.stein@systec-electronic.com> Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, "Wang, Yu" , "Li, Guanglei" , "Wu, Hao" From: Mathias Nyman Message-ID: <589B2889.3050708@linux.intel.com> Date: Wed, 8 Feb 2017 16:17:45 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <20170208134444.18369-1-alexander.stein@systec-electronic.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08.02.2017 15:44, Alexander Stein wrote: > This patch adds support for USB2 test mode (Test_J, Test_K, > Test_SE0_NAK and Test_Packet) per XHCI spec 4.19.6. > > USB2 test mode is a required hardware feature for system integrators > validating their hardware according to USB spec, regarding signal > strength and stuff. It is purely a hardware test feature. > > Usually you need an oscilloscope and have to enable those test modes on > the hardware. This will send some specific test patterns on D+/D-. There > is no report available (in Linux itself) as it is purely externally > visible. Regular USB usage is not possible at that time. > Anyone (well access to e.g. /dev/bus/usb/001/001 provided) can use it by > sending appropriate USB_PORT_FEAT_TEST requests to the hub. > The same feature for ehci based hosts is already available at > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/usb/host/ehci-hub.c#n1267 > > Signed-off-by: "Wang, Yu" > Signed-off-by: "Li, Guanglei" > Signed-off-by: "Wu, Hao" > Signed-off-by: Alexander Stein > --- I think there's a reworked series of this feature already posted at: http://marc.info/?l=linux-usb&m=148050258916147&w=2 But this change log is now better I was thinking about adding that to 4.12 -Mathias