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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 D77BBC43382 for ; Tue, 25 Sep 2018 11:19:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D4C82087A for ; Tue, 25 Sep 2018 11:19:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7D4C82087A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=sntech.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 S1728966AbeIYR0J (ORCPT ); Tue, 25 Sep 2018 13:26:09 -0400 Received: from gloria.sntech.de ([185.11.138.130]:59248 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727606AbeIYR0J (ORCPT ); Tue, 25 Sep 2018 13:26:09 -0400 Received: from wd0156.dip.tu-dresden.de ([141.76.108.156] helo=phil.localnet) by gloria.sntech.de with esmtpsa (TLS1.0:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1g4lMa-0006Bb-9U; Tue, 25 Sep 2018 13:18:44 +0200 From: Heiko Stuebner To: Damian Kos Cc: David Airlie , Rob Herring , Mark Rutland , Archit Taneja , Andrzej Hajda , Laurent Pinchart , Gustavo Padovan , Maarten Lankhorst , Sean Paul , Sandy Huang , Quentin Schulz , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, pgaj@cadence.com, ltyrala@cadence.com, rafalc@cadence.com, jartur@cadence.com, piotrs@cadence.com, quentin.schulz@bootlin.com, jbergsagel@ti.com Subject: Re: [PATCH v5 2/5] drm/dp: fix link probing for devices supporting DP 1.4+ Date: Tue, 25 Sep 2018 13:18:42 +0200 Message-ID: <18095829.BFmvNaydv0@phil> In-Reply-To: <1537866837-4408-3-git-send-email-dkos@cadence.com> References: <1537866837-4408-1-git-send-email-dkos@cadence.com> <1537866837-4408-3-git-send-email-dkos@cadence.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Damian, Am Dienstag, 25. September 2018, 11:13:32 CEST schrieb Damian Kos: > From: Quentin Schulz > > DP 1.4 introduced a DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT bit in > DP_TRAINING_AUX_RD_INTERVAL register. If set, DPCD registers from > DP_DPCD_REV to DP_ADAPTER_CAP should be retrieved starting from > DP_DPCD_REV_EXTENDED. All registers are copied except DP_DPCD_REV, > DP_MAX_LINK_RATE and DP_DOWNSTREAMPORT_PRESENT which represent the > "true capabilities" of DPRX device. > > Original DP_DPCD_REV, DP_MAX_LINK_RATE and DP_DOWNSTREAMPORT_PRESENT > might falsely return lower capabilities to "avoid interoperability > issues with some of the existing DP Source devices that malfunction > when they discover the higher capabilities within those three > registers.". > > Before DP 1.4, DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT bit was reserved > and read 0 so it's safe to check against it even if DP revision is > <1.4 > > Signed-off-by: Quentin Schulz > Signed-off-by: Damian Kos in v4 you received a Reviewed-by: Manasi Navare for this patch. If a patch is largely unchanged from one version to another please add these previously received tags to the commit message. This prevents people from reviewing needlessly stuff twice ;-) . So the above should read ----- 8< ----- Signed-off-by: Quentin Schulz Signed-off-by: Damian Kos Reviewed-by: Manasi Navare ----- 8< ----- Heiko