From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932437AbaKRVqF (ORCPT ); Tue, 18 Nov 2014 16:46:05 -0500 Received: from smtprelay.synopsys.com ([198.182.44.111]:43294 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753300AbaKRVqC convert rfc822-to-8bit (ORCPT ); Tue, 18 Nov 2014 16:46:02 -0500 From: Paul Zimmerman To: "balbi@ti.com" , Jorge Ramirez-Ortiz CC: Greg KH , "linux-kernel@vger.kernel.org" , "linux-usb@vger.kernel.org" Subject: RE: [PATCH] usb: gadget: USB3 support to the legacy printer driver Thread-Topic: [PATCH] usb: gadget: USB3 support to the legacy printer driver Thread-Index: AQHQAr0NM6ip+f4vtE6njx4rWhy/JpxmDlYAgADnqACAABBJgIAAKxyAgAACXoCAAC0AgIAAAYQA//+INAA= Date: Tue, 18 Nov 2014 21:45:13 +0000 Message-ID: References: <546A829A.8030106@linaro.org> <20141118003028.GA11280@saruman> <546B5578.8040809@linaro.org> <20141118151753.GB8223@saruman> <546B874B.8060700@linaro.org> <20141118180039.GJ6179@saruman> <546BAF07.1050605@linaro.org> <20141118204708.GR6179@saruman> In-Reply-To: <20141118204708.GR6179@saruman> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.9.64.240] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > From: linux-usb-owner@vger.kernel.org [mailto:linux-usb-owner@vger.kernel.org] On Behalf Of Felipe Balbi > Sent: Tuesday, November 18, 2014 12:47 PM > > On Tue, Nov 18, 2014 at 03:41:43PM -0500, Jorge Ramirez-Ortiz wrote: > > > > notice that the original PLX driver was still far from the theoretical 5Gbps > > target (I was expecting to measure at least 3Gbps and could only get 1Gbps). > > So 1Gbps should be the target to meet on the kernel.org net2280 - do you agree? > > this depends on a whole bunch of things. Mainline is a lot different > from PLX's kernel tree, I'm sure. > > It also depends on how many PCIe lanes you're using. Just because USB3 > guarantees 5Gbps bandwidth, if you use a 1x PCIe connector, you'll never > get that ;-) Being pedantic, USB3 runs at 4Gbps, not 5Gbps. The signal transitions on the bus are at 5GT/s (5 giga-transitions per second), but due to the 8b/10b encoding, that equates to 4Gbps data rate. -- Paul