Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751856AbaDAWBO (ORCPT ); Tue, 1 Apr 2014 18:01:14 -0400 Received: from netrider.rowland.org ([192.131.102.5]:35578 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751450AbaDAWBM (ORCPT ); Tue, 1 Apr 2014 18:01:12 -0400 Date: Tue, 1 Apr 2014 18:01:11 -0400 (EDT) From: Alan Stern X-X-Sender: stern@netrider.rowland.org To: Julius Werner cc: Sarah Sharp , Mathias Nyman , Greg Kroah-Hartman , "linux-usb@vger.kernel.org" , LKML , Vincent Palatin , Andrew Bresticker , Jim Lin Subject: Re: [PATCH] usb: xhci: Correct last context entry calculation for Configure Endpoint In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 1 Apr 2014, Julius Werner wrote: > > http://marc.info/?l=linux-usb&m=137158978503741&w=2 > > > > There's an xHCI spec ambiguity: Does the last valid context entry refer > > to the last valid endpoint context in the *input* device context or the > > *output* device context? It's not ambiguous at all. 6.2.2.2 clearly states: A 'valid' Input Slot Context for a Configure Endpoint Command requires the Context Entries field to be initialized to the index of the last valid Endpoint Context that is defined by the _target configuration_. (my emphasis). Thus, if the current config has ep0, ep1, and ep2 and the command drops ep1, the Context Entries field should be set to the index of ep2 since that is the last valid Endpoint Context in the target config (which has only ep0 and ep2). Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/