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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55666C433EF for ; Tue, 21 Jun 2022 14:32:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351664AbiFUOb7 (ORCPT ); Tue, 21 Jun 2022 10:31:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351344AbiFUOb4 (ORCPT ); Tue, 21 Jun 2022 10:31:56 -0400 Received: from smtp96.ord1d.emailsrvr.com (smtp96.ord1d.emailsrvr.com [184.106.54.96]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A485A248E0; Tue, 21 Jun 2022 07:31:55 -0700 (PDT) X-Auth-ID: markh@compro.net Received: by smtp5.relay.ord1d.emailsrvr.com (Authenticated sender: markh-AT-compro.net) with ESMTPSA id 7C1B5A0156; Tue, 21 Jun 2022 10:31:54 -0400 (EDT) Message-ID: <5ca9f8d7-0a64-ad5a-f421-99380df8f9b9@compro.net> Date: Tue, 21 Jun 2022 10:31:54 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 Reply-To: markh@compro.net Subject: Re: [BUG] dma-mapping: remove CONFIG_DMA_REMAP Content-Language: en-US To: Christoph Hellwig Cc: Robin Murphy , Linux-kernel , dmaengine@vger.kernel.org References: <20220621134837.GA8025@lst.de> <9de341bc-fe8d-1820-187a-46455e4b9bf2@compro.net> <20220621141924.GA8348@lst.de> From: Mark Hounschell Organization: Compro Computer Svcs. In-Reply-To: <20220621141924.GA8348@lst.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Classification-ID: ac4a7eef-7c6c-4bfd-a4fc-0ff2dd8cea6b-1-1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/21/22 10:19, Christoph Hellwig wrote: > On Tue, Jun 21, 2022 at 10:06:59AM -0400, Mark Hounschell wrote: >> On 6/21/22 09:48, Christoph Hellwig wrote: >>> On Tue, Jun 21, 2022 at 09:43:18AM -0400, Mark Hounschell wrote: >>>> Revert that commit and all works like normal. This commit breaks user land. >>> >>> No. We had that discussion before. It exposeѕ how broken your out of >>> tree driver is, which you don't bother to fix despite Robin even taking >>> the pains to explain you how. >> >> No, this is not the original issue and we never actually had a discussion. >> That original issue was about using Set/ClearPageReserved. You nor Robin >> even tried to explain why it was wrong to use it. It was never an issue in >> previous kernels. Why now? In any case I have removed that code. This is >> what happens now. >> >> What is it you think I am doing wrong. Except for using >> Set/ClearPageReserved you have not explained anything to me. > > Which part of "you must not call virt_to_page on the result that is > very clearly stated in the documentation and has been explained to > you repeatly" is still not clear to you? > That has not been explained to me at all. I am NOT any longer using virt_to_page at all anywhere in the driver. I was told that Set/ClearPageReserve was what I was doing wrong. Not that I was using virt_to_page with it. I am not using either now. I am using only dma_alloc_coherent. > Which part of "if your of tree modules stops working, this does not > constitute userspace breakage" is not clear to you? > > I'm done with this, please stop bothering me. I am not trying to bother you and there is no reason for you to be rude to me. I just think this is a bug and am trying to get to the bottom of it. Regards Mark