From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:58492 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725780AbfFNPaf (ORCPT ); Fri, 14 Jun 2019 11:30:35 -0400 Date: Fri, 14 Jun 2019 17:30:32 +0200 From: Greg KH Subject: Re: [PATCH 12/16] staging/comedi: mark as broken Message-ID: <20190614153032.GD18049@kroah.com> References: <20190614134726.3827-1-hch@lst.de> <20190614134726.3827-13-hch@lst.de> <20190614140239.GA7234@kroah.com> <20190614144857.GA9088@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190614144857.GA9088@lst.de> Sender: linux-s390-owner@vger.kernel.org List-ID: To: Christoph Hellwig Cc: Maarten Lankhorst , Maxime Ripard , Sean Paul , David Airlie , Daniel Vetter , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Ian Abbott , H Hartley Sweeten , devel@driverdev.osuosl.org, linux-s390@vger.kernel.org, Intel Linux Wireless , linux-rdma@vger.kernel.org, netdev@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, "moderated list:ARM PORT" , linux-media@vger.kernel.org On Fri, Jun 14, 2019 at 04:48:57PM +0200, Christoph Hellwig wrote: > On Fri, Jun 14, 2019 at 04:02:39PM +0200, Greg KH wrote: > > Perhaps a hint as to how we can fix this up? This is the first time > > I've heard of the comedi code not handling dma properly. > > It can be fixed by: > > a) never calling virt_to_page (or vmalloc_to_page for that matter) > on dma allocation > b) never remapping dma allocation with conflicting cache modes > (no remapping should be doable after a) anyway). Ok, fair enough, have any pointers of drivers/core code that does this correctly? I can put it on my todo list, but might take a week or so... Ian, want to look into doing this sooner? thanks, greg k-h