Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752472AbdLEOei (ORCPT ); Tue, 5 Dec 2017 09:34:38 -0500 Received: from mga05.intel.com ([192.55.52.43]:46686 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751255AbdLEOeh (ORCPT ); Tue, 5 Dec 2017 09:34:37 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.45,364,1508828400"; d="scan'208";a="181549520" Subject: Re: [PATCH v3 9/9] drm/i915: Implement HDCP for DisplayPort To: Sean Paul , dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Cc: seanpaul@google.com, David Airlie , Joonas Lahtinen , linux-kernel@vger.kernel.org, Rodrigo Vivi , daniel.vetter@intel.com References: <20171205051513.8603-1-seanpaul@chromium.org> <20171205051513.8603-10-seanpaul@chromium.org> From: Ramalingam C Message-ID: <49e69878-1fcf-1d46-218c-28cae11c7def@intel.com> Date: Tue, 5 Dec 2017 20:00:57 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <20171205051513.8603-10-seanpaul@chromium.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 663 Lines: 23 On Tuesday 05 December 2017 10:45 AM, Sean Paul wrote: > +static > +bool intel_dp_hdcp_check_link(struct intel_digital_port *intel_dig_port) > +{ > + ssize_t ret; > + u8 bstatus; > + ret = drm_dp_dpcd_read(&intel_dig_port->dp.aux, DP_AUX_HDCP_BSTATUS, > + &bstatus, 1); > + if (ret != 1) { > + DRM_ERROR("Read bstatus from DP/AUX failed (%ld)\n", ret); > + return ret >= 0 ? -EIO : ret; > + } > + return !(bstatus & DP_BSTATUS_LINK_FAILURE); > +} as per link integrity check should cover other indication from the repeater like REAUTHENTICATION_REQUEST - request for reauth due to unauthenticated state at downstream for some unknown reason -Ram