From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757069Ab2HQXKu (ORCPT ); Fri, 17 Aug 2012 19:10:50 -0400 Received: from home.keithp.com ([63.227.221.253]:52321 "EHLO keithp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756691Ab2HQXKm (ORCPT ); Fri, 17 Aug 2012 19:10:42 -0400 From: Keith Packard To: "Lespiau\, Damien" Cc: intel-gfx@lists.freedesktop.org, Daniel Vetter , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: Re: [Intel-gfx] [PATCH 6/7] drm/i915: Disable FDI RX before FDI TX In-Reply-To: References: <1344918891-6283-1-git-send-email-keithp@keithp.com> <1344918891-6283-7-git-send-email-keithp@keithp.com> User-Agent: Notmuch/0.13.2 (http://notmuchmail.org) Emacs/23.4.1 (i486-pc-linux-gnu) Date: Fri, 17 Aug 2012 16:10:57 -0700 Message-ID: <86393lunb2.fsf@miki.keithp.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-=-= Content-Transfer-Encoding: quoted-printable "Lespiau, Damien" writes: > I can't see anything in the docs about an order requirement for those. Right, the docs don't say anything, which is a bit disconcerting. > Not sure why the other way does not make sense. Somehow disabling TX > before RX makes some sense to me (TX enabled without a ready RX looks > weird?, no data should flow as the pipe is shutdown at that point > anyway). Maybe it just does not matter? And here I figured disabling RX before TX made more sense -- otherwise the receiver wouldn't be seeing anything. In other areas of the driver, we're careful to disable receivers before senders (disable CRTC before PLL, etc). > Another detail is that disabling the PLLs seem to have an order in the > disabling sequence, TX, then RX. > > I. Disable CPU FDI Transmitter PLL > II. Disable PCH FDI Receiver PLL That ordering doesn't matter as the FDI receiver and transmitter are both disabled by that point, so they aren't talking at all. =2D-=20 keith.packard@intel.com --=-=-= Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIVAwUBUC7PgjYtFsjWk68qAQgAkg//ROGG75eVoPQR/7gw4Vo+m5IQEyriAXOi bkYY++p4UPv/3ky4Roww/yxEE7wORTi0/C8ORAeYy+UPmHvWc84he2xdO2hZmbu2 9tF5bVkuem5SY7iJXR8df2Il/7jZ5ygAwykbOeA6wCBzyX7egNJvDMhszD9xdakI JprPoUS6QUPdwL+2irN9mi+ftLfJDmauK2IBSdwvi2UXQuZnHGR93Smrmzuv00QJ LMWYZR52+g34q9GcyiQQ1Jhl59NvVzBfNTsKMeViskhIDU0Q7Nxa6sPeAy2fgpad 968g4x2RQd0J93IVfYsUKnJT3txBrbjjucJ1GvokvV24USlbL2O51ZnUkIjypawy k5E3yR2qQBey7PL4zRJAmbt4Rs63XJkH6yd44pQyCAgtUnKke/bw5aenSwqY8b+M 8VQry5bKi4Vqmh89c2MtqdZwSUT5oAiDAzjQJ7F4k3D2Fo0NPMaaN+Cdecz6MADo AqWF+bmx8tU1SCT9syEIEotM+NTnU3xyzHXa0geqW0d+h0efmnDzwpNnFa4AhScB s6aoovzNWW0U1JE2iHTTKfeT2gMvzupCA+z++geoE1s90HWQNfIHLlIbJtppmQ3O SxqvfPx69NjK1xRSGrcfInUFLsoQ8nNXdJa55QKDvt9W7HboCq0n9NV/ld/HCjpz EqaraMKpze8= =26Nr -----END PGP SIGNATURE----- --=-=-=--