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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 1068EC433F4 for ; Tue, 18 Sep 2018 22:16:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B979621471 for ; Tue, 18 Sep 2018 22:16:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B979621471 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=the-dreams.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728249AbeISDva (ORCPT ); Tue, 18 Sep 2018 23:51:30 -0400 Received: from sauhun.de ([88.99.104.3]:46150 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727987AbeISDva (ORCPT ); Tue, 18 Sep 2018 23:51:30 -0400 Received: from localhost (mue-88-130-102-194.dsl.tropolys.de [88.130.102.194]) by pokefinder.org (Postfix) with ESMTPSA id 50C862C0590; Wed, 19 Sep 2018 00:16:47 +0200 (CEST) Date: Wed, 19 Sep 2018 00:16:46 +0200 From: Wolfram Sang To: Stephen Boyd Cc: linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, linux-arm-msm@vger.kernel.org, Karthikeyan Ramasubramanian , Sagar Dharia , Girish Mahadevan Subject: Re: [PATCH] i2c: i2c-qcom-geni: Properly handle DMA safe buffers Message-ID: <20180918221646.GA970@kunai> References: <20180918194126.138455-1-swboyd@chromium.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="k+w/mQv8wyuph6w0" Content-Disposition: inline In-Reply-To: <20180918194126.138455-1-swboyd@chromium.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --k+w/mQv8wyuph6w0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline > This fixes a problem where the kernel oopses cleaning pages for a buffer > that's mapped into the vmalloc space. The pages are returned from > request_firmware() and passed down directly to the i2c master to write > to the i2c touchscreen device. Mapping vmalloc buffers with > dma_map_single() won't work reliably, causing an oops like below: Exactly the reason why I implemented I2C_M_DMA_SAFE. Did you also notice the helper i2c_get_dma_safe_msg_buf() which you maybe could use for len > 32? --k+w/mQv8wyuph6w0 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAluheUoACgkQFA3kzBSg KbY5lg/+O6lcx0uYmTjDHz7bfAO3QH49D9q7kDhqGBmwkQ1szR0WtXQCF9oOmIKS 8yytXNLqBhMyijpcBeQ62iNk/FW2f6A7+wYSjsElC7lWmqgGsNtotTJqRVAYDtlK 5u9BgG3lAC40c7boLNzQ+5/3ivbxP/B+0nmoHcOpE9eRRHobwF87jkvMZILKxiCM UgWjpheCWALbYItbkPSiLJTpxq8VtJZAwHNwuKctiPCG6tpQquJ903tBZs7VfAwU 3AUPhwalNLaK3QaZVwM2RAGW0H0FcCz/TsgpkWFoirGdxvE/wGWXIDe6Uoeet+7U e3ltKNKc830tu4V8Tm6YYb2SfYquNbgQmsP2TnOmrqGsyNRZbTZEwIXJ4i8UkuyK 0Xwyzc23b0uReUF7mztp1p76eWaHl9/Rohk7EFmK9C+jnzg4rhj9WdIrtdxdQ54K jwewNdmdkE06YS3x90ngONaONBnEuF0IM5VlKTT53mnFwpQl6ILd8p42qY6LFey9 lwhRuyhgURHd5GCvCNiNAJa240W26FKZwT96aZQjubPTb45wpYeoJNo8JbPHLB4n Juxscuv2/Cf+yXGT4nH8/G8uqQnZfW8gvftGSxDxqevWcb09fIovxnbJqrhqSTuO Aw9i6yzFYg+s4tvkQ1fCn6iKHVsaH25J2O2xH57ZnxBxhvb1WAg= =UwD6 -----END PGP SIGNATURE----- --k+w/mQv8wyuph6w0--