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=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_MUTT 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 CD9CFC31E4B for ; Fri, 14 Jun 2019 15:30:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9635B2177E for ; Fri, 14 Jun 2019 15:30:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560526242; bh=yHr9pq/10KysBErHEUNYe66X5QjENZmZbRJgZ95Q5/o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Dvj8D0YVMbJxVzzoftxFX04Um4GUNwVbD/drgW6LeC8b4rhYs9pNNfNe+aZS8Y/N9 xfi3dd6KZzskMyFZBJn6LBxKzn2EILXWtqLH7ZoedTOYyHihk5BunmfPeOlVEKJgIR tZzlt5hL8hABjMkbOGQdZ8L0kYWwvHlktys8vJJ8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726193AbfFNPaf (ORCPT ); Fri, 14 Jun 2019 11:30:35 -0400 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 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CD9E42175B; Fri, 14 Jun 2019 15:30:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560526234; bh=yHr9pq/10KysBErHEUNYe66X5QjENZmZbRJgZ95Q5/o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YQSkaSpALbREELFlyjYwtyXX2zZ40opkg5+4KefS4XBIuG2ytKNe/HlyefrPeKCy0 E/FugLo4jefFccnnPx66ACowyYQe8Bea79xHMfRvngOsTctElVKuYIxt72NvyX9Rye Xmh7GqKPGUeRorB/KJsSF7isbiZer4sAIhDPDf20= Date: Fri, 14 Jun 2019 17:30:32 +0200 From: Greg KH 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 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> User-Agent: Mutt/1.12.0 (2019-05-25) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: 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