From patchwork Mon Feb 26 17:12:36 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ramalingam C X-Patchwork-Id: 10242847 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D93F8602A0 for ; Mon, 26 Feb 2018 17:18:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CFA152A1F7 for ; Mon, 26 Feb 2018 17:18:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C48242A1FA; Mon, 26 Feb 2018 17:18:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 856822A1F7 for ; Mon, 26 Feb 2018 17:18:46 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 10BA36E4F4; Mon, 26 Feb 2018 17:18:44 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7D0486E4F4; Mon, 26 Feb 2018 17:18:41 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Feb 2018 09:18:41 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.47,397,1515484800"; d="scan'208";a="203873717" Received: from mint-dev.iind.intel.com ([10.223.25.164]) by orsmga005.jf.intel.com with ESMTP; 26 Feb 2018 09:18:39 -0800 From: Ramalingam C To: intel-gfx@lists.freedesktop.org, seanpaul@chromium.org, dri-devel@lists.freedesktop.org Subject: [PATCH 2/5] drm/i915: read Vprime thrice incase of mismatch Date: Mon, 26 Feb 2018 22:42:36 +0530 Message-Id: <1519665159-28639-3-git-send-email-ramalingam.c@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1519665159-28639-1-git-send-email-ramalingam.c@intel.com> References: <1519665159-28639-1-git-send-email-ramalingam.c@intel.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP In case of V prime mismatch, DP HDCP spec mandates the re-read of Vprime atleast twice. DP HDCP CTS Test: 1B-05 Signed-off-by: Ramalingam C --- drivers/gpu/drm/i915/intel_hdcp.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c index 730681d2dbfb..7ea55fa46f41 100644 --- a/drivers/gpu/drm/i915/intel_hdcp.c +++ b/drivers/gpu/drm/i915/intel_hdcp.c @@ -150,7 +150,7 @@ int intel_hdcp_auth_downstream(struct intel_digital_port *intel_dig_port, struct drm_i915_private *dev_priv; u32 vprime, sha_text, sha_leftovers, rep_ctl; u8 bstatus[2], num_downstream, *ksv_fifo; - int ret, i, j, sha_idx; + int ret, i, j, sha_idx, tries = 3; dev_priv = intel_dig_port->base.base.dev->dev_private; @@ -189,6 +189,7 @@ int intel_hdcp_auth_downstream(struct intel_digital_port *intel_dig_port, if (ret) return ret; +read_v_prime: /* Process V' values from the receiver */ for (i = 0; i < DRM_HDCP_V_PRIME_NUM_PARTS; i++) { ret = shim->read_v_prime_part(intel_dig_port, i, &vprime); @@ -385,6 +386,13 @@ int intel_hdcp_auth_downstream(struct intel_digital_port *intel_dig_port, return -ETIMEDOUT; } if (!(I915_READ(HDCP_REP_CTL) & HDCP_SHA1_V_MATCH)) { + + /* + * When V prime mismatches, DP Spec mandates re-read of + * V prime atleast twice. + */ + if (--tries) + goto read_v_prime; DRM_ERROR("SHA-1 mismatch, HDCP failed\n"); return -ENXIO; }