Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751204AbaKXU4d (ORCPT ); Mon, 24 Nov 2014 15:56:33 -0500 Received: from www.linutronix.de ([62.245.132.108]:41299 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750734AbaKXU4c (ORCPT ); Mon, 24 Nov 2014 15:56:32 -0500 Message-ID: <54739B7C.7020102@linutronix.de> Date: Mon, 24 Nov 2014 21:56:28 +0100 From: Sebastian Andrzej Siewior User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.2.0 MIME-Version: 1.0 To: Felipe Balbi , George Cherian , gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] usb: musb: core: Disable the Interrupts till BABBLE is fully handled References: <1415953486-6000-1-git-send-email-george.cherian@ti.com> <20141118211734.GA19146@saruman> <54736FBE.6060505@linutronix.de> <20141124182053.GD25712@saruman> <20141124203908.4425.qmail@stuge.se> In-Reply-To: <20141124203908.4425.qmail@stuge.se> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/24/2014 09:39 PM, Peter Stuge wrote: > Felipe Balbi wrote: >>>> A babble only occurs when >>>> the device side tries to move data without the host asking for anything. >>> >>> It also occurs if the device moves more than packet_size bytes. Not >>> really helping, I know… >> >> hmm, why would the device move more than wMaxPacketSize at a time ? > > Some devices are buggy. for instance if the device comes out of resume and the clock is not yet stable but the device sends data. That is not the case here, but an example :) I *think* for some reason the host did not really receive ep0 set_config request as planned. And device's answer is probably then interpreted as data which is not expected (as Felipe said "device side tries to move data without the host asking for anything"). >> That's certainly babble :-) > > Certainly! But musb shouldn't fall over or lock up because of it, should it? No and the patch fixes the issue. The strange thing is that it only happens on the same device. Not if you connect host<->device with two boards. > //Peter > Sebastian -- 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/