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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 5B490C4338F for ; Wed, 25 Aug 2021 14:30:31 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 256B5610C8 for ; Wed, 25 Aug 2021 14:30:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 256B5610C8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 649E36E237; Wed, 25 Aug 2021 14:30:30 +0000 (UTC) Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTPS id 005486E237; Wed, 25 Aug 2021 14:30:28 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10086"; a="217252962" X-IronPort-AV: E=Sophos;i="5.84,350,1620716400"; d="scan'208";a="217252962" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Aug 2021 07:30:28 -0700 X-IronPort-AV: E=Sophos;i="5.84,350,1620716400"; d="scan'208";a="527347137" Received: from mburkard-mobl1.ger.corp.intel.com (HELO localhost) ([10.251.213.64]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Aug 2021 07:30:26 -0700 From: Jani Nikula To: Ville =?utf-8?B?U3lyasOkbMOk?= Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Manasi Navare In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: Date: Wed, 25 Aug 2021 17:30:23 +0300 Message-ID: <87eeahegw0.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Intel-gfx] [PATCH 2/4] drm/dp: use more of the extended receiver cap X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Thu, 19 Aug 2021, Ville Syrj=C3=A4l=C3=A4 wrote: > On Fri, Aug 13, 2021 at 01:43:20PM +0300, Jani Nikula wrote: >> Extend the use of extended receiver cap at 0x2200 to cover >> MAIN_LINK_CHANNEL_CODING_CAP in 0x2206, in case an implementation hides >> the DP 2.0 128b/132b channel encoding cap. >>=20 >> Cc: Manasi Navare >> Signed-off-by: Jani Nikula >> --- >> drivers/gpu/drm/drm_dp_helper.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >>=20 >> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_he= lper.c >> index 9b2a2961fca8..9389f92cb944 100644 >> --- a/drivers/gpu/drm/drm_dp_helper.c >> +++ b/drivers/gpu/drm/drm_dp_helper.c >> @@ -608,7 +608,7 @@ static u8 drm_dp_downstream_port_count(const u8 dpcd= [DP_RECEIVER_CAP_SIZE]) >> static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux, >> u8 dpcd[DP_RECEIVER_CAP_SIZE]) >> { >> - u8 dpcd_ext[6]; >> + u8 dpcd_ext[DP_MAIN_LINK_CHANNEL_CODING + 1]; > > Why are we even reading less of this than the normal receiver caps? Good question. I forget my reasoning to only extend to what might affect this use case. Should we extend to the size of the usual receiver caps? BR, Jani. > >> int ret; >>=20=20 >> /* >> --=20 >> 2.20.1 --=20 Jani Nikula, Intel Open Source Graphics Center