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 B486DC56201 for ; Tue, 24 Nov 2020 10:27:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6D3642087D for ; Tue, 24 Nov 2020 10:27:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731987AbgKXK1S (ORCPT ); Tue, 24 Nov 2020 05:27:18 -0500 Received: from verein.lst.de ([213.95.11.211]:53857 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731828AbgKXK1S (ORCPT ); Tue, 24 Nov 2020 05:27:18 -0500 Received: by verein.lst.de (Postfix, from userid 2407) id 8AE1867373; Tue, 24 Nov 2020 11:27:15 +0100 (CET) Date: Tue, 24 Nov 2020 11:27:15 +0100 From: Christoph Hellwig To: Hans de Goede Cc: Mathias Nyman , Greg Kroah-Hartman , Christoph Hellwig , linux-usb , Linux Kernel Mailing List , linux-pci@vger.kernel.org Subject: Re: 5.10 regression, many XHCI swiotlb buffer is full / DMAR: Device bounce map failed errors on thunderbolt connected XHCI controller Message-ID: <20201124102715.GA16983@lst.de> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Mon, Nov 23, 2020 at 03:49:09PM +0100, Hans de Goede wrote: > Hi, > > +Cc Christoph Hellwig > > Christoph, this is still an issue, so I've been looking around a bit and think this > might have something to do with the dma-mapping-5.10 changes. > > Do you have any suggestions to debug this, or is it time to do a git bisect > on this before 5.10 ships with regression? Given that DMAR prefix this seems to be about using intel-iommu + bounce buffering for external devices. I can't really think of anything specific in 5.10 related to that, so maybe you'll need to bisect. I doub this means we are actually leaking swiotlb buffers, so while I'm pretty sure we broke something in lower layers this also means xhci doesn't handle swiotlb operation very gracefully in general.