From patchwork Mon Feb 5 17:32:02 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ramalingam C X-Patchwork-Id: 10201007 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 6ECDE601A1 for ; Mon, 5 Feb 2018 17:37:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5E04B2860B for ; Mon, 5 Feb 2018 17:37:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4EE412877C; Mon, 5 Feb 2018 17:37:47 +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 4E8FB2860B for ; Mon, 5 Feb 2018 17:37:46 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A339E89A20; Mon, 5 Feb 2018 17:37:44 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTPS id F27E189A20 for ; Mon, 5 Feb 2018 17:37:43 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Feb 2018 09:37:43 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,465,1511856000"; d="scan'208";a="28948293" Received: from mint-dev.iind.intel.com ([10.223.25.164]) by orsmga001.jf.intel.com with ESMTP; 05 Feb 2018 09:37:41 -0800 From: Ramalingam C To: seanpaul@chromium.org, intel-gfx@lists.freedesktop.org Date: Mon, 5 Feb 2018 23:02:02 +0530 Message-Id: <1517851922-30547-1-git-send-email-ramalingam.c@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1517850881-31333-1-git-send-email-ramalingam.c@intel.com> References: <1517850881-31333-1-git-send-email-ramalingam.c@intel.com> Subject: [Intel-gfx] [PATCH v5] drm/i915: Retry HDCP bksv read X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP HDCP specification says that when bksv is identified as invalid (not with 20 1s), bksv should be re-read and verified. This patch adds the above mentioned re-read for bksv. v2: Rephrased the commit msg [Seanpaul] v3: do-while to for-loop [Seanpaul] v4: retry only if bksv is invalid and no error msg on each attempt [Seanpaul] v5: Correcting the return value [Seanpaul]. Signed-off-by: Ramalingam C --- drivers/gpu/drm/i915/intel_hdcp.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c index cfd13ee8c534..d7ddd6b28cd7 100644 --- a/drivers/gpu/drm/i915/intel_hdcp.c +++ b/drivers/gpu/drm/i915/intel_hdcp.c @@ -397,7 +397,7 @@ static int intel_hdcp_auth(struct intel_digital_port *intel_dig_port, struct drm_i915_private *dev_priv; enum port port; unsigned long r0_prime_gen_start; - int ret, i; + int ret, i, tries = 2; union { u32 reg[2]; u8 shim[DRM_HDCP_AN_LEN]; @@ -438,11 +438,19 @@ static int intel_hdcp_auth(struct intel_digital_port *intel_dig_port, r0_prime_gen_start = jiffies; memset(&bksv, 0, sizeof(bksv)); - ret = shim->read_bksv(intel_dig_port, bksv.shim); - if (ret) - return ret; - else if (!intel_hdcp_is_ksv_valid(bksv.shim)) + + /* HDCP spec states that we must retry the bksv if it is invalid */ + for (i = 0; i < tries; i++) { + ret = shim->read_bksv(intel_dig_port, bksv.shim); + if (ret) + return ret; + if (intel_hdcp_is_ksv_valid(bksv.shim)) + break; + } + if (i == tries) { + DRM_ERROR("HDCP failed, Bksv is invalid\n"); return -ENODEV; + } I915_WRITE(PORT_HDCP_BKSVLO(port), bksv.reg[0]); I915_WRITE(PORT_HDCP_BKSVHI(port), bksv.reg[1]);