From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754156AbdCIJoj (ORCPT ); Thu, 9 Mar 2017 04:44:39 -0500 Received: from mail-lf0-f44.google.com ([209.85.215.44]:33178 "EHLO mail-lf0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753291AbdCIJoh (ORCPT ); Thu, 9 Mar 2017 04:44:37 -0500 Subject: Re: [PATCH] usb: xhci: bInterval quirk for TI TUSB73x0 To: Roger Quadros , mathias.nyman@intel.com References: <1489049268-30607-1-git-send-email-rogerq@ti.com> Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org From: Sergei Shtylyov Message-ID: <235e20da-ad1c-d417-02e8-962eaf657d1d@cogentembedded.com> Date: Thu, 9 Mar 2017 12:44:33 +0300 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <1489049268-30607-1-git-send-email-rogerq@ti.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! On 3/9/2017 11:47 AM, Roger Quadros wrote: > As per [1] issue #4, > "The periodic EP scheduler always tries to schedule the EPs > that have large intervals (interval equal to or greater than > 128 microframes) into different microframes. So it maintains > an internal counter and increments for each large interval > EP added. When the counter is greater than 128, the scheduler > rejects the new EP. So when the hub re-enumerated 128 times, > it trigged this condition." Triggered. > This results in Bandwidth error when devices with periodic > endpoints (ISO/INT) having bInterval > 7 are plugged an > unplugged several times on a TUSB73x0 xhci host. > > Workaround this issue by limiting the bInterval to 7 > (i.e. interval to 6) for High-speed or faster periodic endpoints. > > [1] - http://www.ti.com/lit/er/sllz076/sllz076.pdf > > Signed-off-by: Roger Quadros [...] MBR, Sergei