From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4BE28C47087 for ; Fri, 28 May 2021 15:35:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E39A6124B for ; Fri, 28 May 2021 15:35:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234338AbhE1Pg4 (ORCPT ); Fri, 28 May 2021 11:36:56 -0400 Received: from relay12.mail.gandi.net ([217.70.178.232]:51399 "EHLO relay12.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230201AbhE1Pgy (ORCPT ); Fri, 28 May 2021 11:36:54 -0400 Received: (Authenticated sender: alexandre.belloni@bootlin.com) by relay12.mail.gandi.net (Postfix) with ESMTPSA id CDA4E200006; Fri, 28 May 2021 15:35:17 +0000 (UTC) Date: Fri, 28 May 2021 17:35:17 +0200 From: Alexandre Belloni To: Thomas Petazzoni Cc: Bin Liu , Greg Kroah-Hartman , Tony Lindgren , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] usb: musb: fix MUSB_QUIRK_B_DISCONNECT_99 handling Message-ID: References: <20210528140446.278076-1-thomas.petazzoni@bootlin.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210528140446.278076-1-thomas.petazzoni@bootlin.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On 28/05/2021 16:04:46+0200, Thomas Petazzoni wrote: > In commit 92af4fc6ec33 ("usb: musb: Fix suspend with devices > connected for a64"), the logic to support the > MUSB_QUIRK_B_DISCONNECT_99 quirk was modified to only conditionally > schedule the musb->irq_work delayed work. > > This commit badly breaks ECM Gadget on AM335X. Indeed, with this > commit, one can observe massive packet loss: > > $ ping 192.168.0.100 > ... > 15 packets transmitted, 3 received, 80% packet loss, time 14316ms > > Reverting this commit brings back a properly functioning ECM > Gadget. An analysis of the commit seems to indicate that a mistake was > made: the previous code was not falling through into the > MUSB_QUIRK_B_INVALID_VBUS_91, but now it is, unless the condition is > taken. > > Changing the logic to be as it was before the problematic commit *and* > only conditionally scheduling musb->irq_work resolves the regression: > > $ ping 192.168.0.100 > ... > 64 packets transmitted, 64 received, 0% packet loss, time 64475ms > > Fixes: 92af4fc6ec33 ("usb: musb: Fix suspend with devices connected for a64") > Signed-off-by: Thomas Petazzoni Tested-by: Alexandre Belloni > Cc: stable@vger.kernel.org > --- > drivers/usb/musb/musb_core.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c > index 8f09a387b773..4c8f0112481f 100644 > --- a/drivers/usb/musb/musb_core.c > +++ b/drivers/usb/musb/musb_core.c > @@ -2009,9 +2009,8 @@ static void musb_pm_runtime_check_session(struct musb *musb) > schedule_delayed_work(&musb->irq_work, > msecs_to_jiffies(1000)); > musb->quirk_retries--; > - break; > } > - fallthrough; > + break; > case MUSB_QUIRK_B_INVALID_VBUS_91: > if (musb->quirk_retries && !musb->flush_irq_work) { > musb_dbg(musb, > -- > 2.31.1 > -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com