From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751555AbdJPIBC (ORCPT ); Mon, 16 Oct 2017 04:01:02 -0400 Received: from mail.free-electrons.com ([62.4.15.54]:46714 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750914AbdJPIBB (ORCPT ); Mon, 16 Oct 2017 04:01:01 -0400 Date: Mon, 16 Oct 2017 10:00:43 +0200 From: Maxime Ripard To: Chen-Yu Tsai Cc: David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com Subject: Re: [PATCH 5/7] drm/sun4i: backend: Offset layer buffer address by DRAM starting address Message-ID: <20171016080043.xqpcxj7xfckcxdem@flea.lan> References: <20171014040252.9621-1-wens@csie.org> <20171014040252.9621-6-wens@csie.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="u4h6i2pbfbk6nea2" Content-Disposition: inline In-Reply-To: <20171014040252.9621-6-wens@csie.org> User-Agent: NeoMutt/20171013 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --u4h6i2pbfbk6nea2 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, I've applied all the other patches. On Sat, Oct 14, 2017 at 12:02:50PM +0800, Chen-Yu Tsai wrote: > The display backend, as well as other peripherals that have a DRAM > clock gate and access DRAM directly, bypassing the system bus, > address the DRAM starting from 0x0, while physical addresses the > system uses starts from 0x40000000 (or 0x20000000 in A80's case). >=20 > Correct the address configured into the backend layer registers > by PHYS_OFFSET to account for this. However, I'm a bit confused at this. The driver has been working so far, which it wouldn't have been able to if the address was wrong. How was this problem noticed, and how can that fix not be an issue in itself? Thanks! Maxime --=20 Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com --u4h6i2pbfbk6nea2 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIcBAEBAgAGBQJZ5GcrAAoJEBx+YmzsjxAghLUQAJ16olYHjcAnqs5p8d8s5Uw/ tBtf9Qv8p34x2WehWynQUOHO4eNHIDdRILxwiVNH/CMcc7HDFRk1FfeseZbclQi9 w3jTTerxV5s5GQwUPh7zsqb2o21bNRpgGS3FXH0d7+zzZXpdzaKMNW9wZi6ZMfas sdpF2MQmStcJwNmKY16MrDRq5m4YtOSjv/p+QPPjDUVTF+KPwAqyWxUEzOXgtCLR tjCMABEp8BrzDlans/FECiv8Piq5j1RgxDtePQmouy61NBL3Dvsb69YF9ddsiles eIoa9jLRxFqtJDYQsj+cTg0w1irGVW9RJYZzRl+fBWqs6ckA+FlQBmwioe8yITOA +wWx4y4VxPoiL8blskPumhUQDAn0alQ3eNgN/Vst4zs+fqwy/MdzfBa3deqzS3yN /hmnsgHYjyB8IVYPK2zeJYe+kBLvg6j6MFqZpgSvDfqBmhjDEhyvYxdzRSVqTQ6n pQ3GbenYZa4F3AWkn9iKmOsvUni7lbNsCwNGy8GARkSXhjvUfjHRHSs3F/qXj8tq s5iF0iRM/nxy5azF6Nhk76qQ8eV8wmAVJPb03VTjjy1HRBkokc69RIQQAfb626VD X15tJhXV1f3057BF16EofpICjdFj/mp79ny5WbLBctEA8F4n+HYFjed1FpZJAOWo 1Xa02Xaqq/wOxjTCfu21 =cLCx -----END PGP SIGNATURE----- --u4h6i2pbfbk6nea2--