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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 1F7EEC433DB for ; Wed, 13 Jan 2021 10:34:32 +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 A7E1822CE3 for ; Wed, 13 Jan 2021 10:34:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A7E1822CE3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D92476E44D; Wed, 13 Jan 2021 10:34:26 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0698B6E44B; Wed, 13 Jan 2021 10:34:25 +0000 (UTC) IronPort-SDR: qyaXFNgrJJA6BrLmdst1bMIbtdNVQrFslEJ0v0hPE/3FyPNJ+ZxSuwxwnv+VL22HsvE29GPzkj q5SlrxZkHD9A== X-IronPort-AV: E=McAfee;i="6000,8403,9862"; a="262970888" X-IronPort-AV: E=Sophos;i="5.79,344,1602572400"; d="scan'208";a="262970888" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jan 2021 02:34:17 -0800 IronPort-SDR: VoDVJ2Kl4wmP9IJ/eHm59zPfEa6T+PlTGS0FAH1DZwVOVqS7lf3Mr4+iwsufjxiquhtlXJxgbq MJjwNiy1QbUA== X-IronPort-AV: E=Sophos;i="5.79,344,1602572400"; d="scan'208";a="567812370" Received: from unknown (HELO intel.com) ([10.223.74.179]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jan 2021 02:34:14 -0800 Date: Wed, 13 Jan 2021 15:49:43 +0530 From: Anshuman Gupta To: Sean Paul Message-ID: <20210113101942.GK11717@intel.com> References: <20210106223909.34476-1-sean@poorly.run> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210106223909.34476-1-sean@poorly.run> User-Agent: Mutt/1.9.4 (2018-02-28) Subject: Re: [Intel-gfx] [PATCH] drm/i915/hdcp: Disable the QSES check for HDCP 1.4 over MST 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: , Cc: David Airlie , "intel-gfx@lists.freedesktop.org" , Sean Paul , "dri-devel@lists.freedesktop.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 2021-01-07 at 04:08:58 +0530, Sean Paul wrote: > From: Sean Paul > > The HDCP 1.4 spec does not require the QUERY_STREAM_ENCRYPTION_STATUS IMHO DP 1.4 vesa specs I.3.5 mark QSES as desirale for both HDCP 1.4 and HDCP 2.2. "The MST Source device may use a QUERY_STREAM_ENCRYPTION_STATUS message transaction to query the downstream status for a particular stream." I feel it useful for scenario in which a non hdcp supported monitor is hot plugged to MST branch. Source really doesn't know about the hdcp capable device on MST branch, it just know the capability of immediate downstream device. QSES can fetch the HDCP capability from MST topology. We don't require to enable stream encryption for such streams. > check, it was always a nice-to-have. After deploying this across various > devices, we've determined that some MST bridge chips do not properly > support this call for HDCP 1.4 (namely Synaptics and Realtek). > > I had considered creating a quirk for this, but I think it's more > prudent to just disable the check entirely since I don't have an idea > how widespread support is. May be we can remove it from the link check and can retain as utility ? Thanks, Anshuman Gupta. > > Signed-off-by: Sean Paul > --- > drivers/gpu/drm/i915/display/intel_dp_hdcp.c | 26 +------------------- > 1 file changed, 1 insertion(+), 25 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c > index 03424d20e9f7..b6a9606bf09a 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c > @@ -640,30 +640,6 @@ intel_dp_mst_hdcp_toggle_signalling(struct intel_digital_port *dig_port, > return ret; > } > > -static > -bool intel_dp_mst_hdcp_check_link(struct intel_digital_port *dig_port, > - struct intel_connector *connector) > -{ > - struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev); > - struct intel_dp *intel_dp = &dig_port->dp; > - struct drm_dp_query_stream_enc_status_ack_reply reply; > - int ret; > - > - if (!intel_dp_hdcp_check_link(dig_port, connector)) > - return false; > - > - ret = drm_dp_send_query_stream_enc_status(&intel_dp->mst_mgr, > - connector->port, &reply); > - if (ret) { > - drm_dbg_kms(&i915->drm, > - "[CONNECTOR:%d:%s] failed QSES ret=%d\n", > - connector->base.base.id, connector->base.name, ret); > - return false; > - } > - > - return reply.auth_completed && reply.encryption_enabled; > -} > - > static const struct intel_hdcp_shim intel_dp_mst_hdcp_shim = { > .write_an_aksv = intel_dp_hdcp_write_an_aksv, > .read_bksv = intel_dp_hdcp_read_bksv, > @@ -674,7 +650,7 @@ static const struct intel_hdcp_shim intel_dp_mst_hdcp_shim = { > .read_ksv_fifo = intel_dp_hdcp_read_ksv_fifo, > .read_v_prime_part = intel_dp_hdcp_read_v_prime_part, > .toggle_signalling = intel_dp_mst_hdcp_toggle_signalling, > - .check_link = intel_dp_mst_hdcp_check_link, > + .check_link = intel_dp_hdcp_check_link, > .hdcp_capable = intel_dp_hdcp_capable, > > .protocol = HDCP_PROTOCOL_DP, > -- > Sean Paul, Software Engineer, Google / Chromium OS > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx