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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 AB6D9C07E9A for ; Wed, 14 Jul 2021 16:27:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8619E61377 for ; Wed, 14 Jul 2021 16:27:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229607AbhGNQau (ORCPT ); Wed, 14 Jul 2021 12:30:50 -0400 Received: from netrider.rowland.org ([192.131.102.5]:37717 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S229576AbhGNQat (ORCPT ); Wed, 14 Jul 2021 12:30:49 -0400 Received: (qmail 385431 invoked by uid 1000); 14 Jul 2021 12:27:57 -0400 Date: Wed, 14 Jul 2021 12:27:57 -0400 From: Alan Stern To: David Jeffery Cc: linux-usb@vger.kernel.org, Laurence Oberman , Andy Shevchenko , Ewan Milne , apanagio@redhat.com, torez@redhat.com Subject: Re: [PATCH] usb: ehci: Prevent missed ehci interrupts with edge-triggered MSI Message-ID: <20210714162757.GD380727@rowland.harvard.edu> References: <20210714140309.GA27799@redhat> <20210714142923.GA380727@rowland.harvard.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Wed, Jul 14, 2021 at 12:10:26PM -0400, David Jeffery wrote: > On Wed, Jul 14, 2021 at 10:29 AM Alan Stern wrote: > > > > Does this issue affect any other PCI-based host controller drivers? > > > > Alan Stern > > > > Possibly. The uhci driver should have the same issue if hardware > exists with it and has MSI for it. I suspect the ohci driver has a > similar issue, but I'm not familiar enough with its interfaces and > specification to say for sure. Hmmm. I've never heard of an MSI implementation of either of those, although it may be possible for OHCI. UHCI was used only by Intel and one or two others; as far as I know none of them are producing those controllers any more. Nowadays when people want to support USB-1.1 devices but not USB-3, they use an EHCI controller together with a "rate-matching" hub, which avoids the need for any UHCI or OHCI controller. I was wondering more about dwc2 or other non-EHCI USB-2 controller drivers. Alan Stern