From patchwork Thu Feb 22 07:43:54 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kandpal, Suraj" X-Patchwork-Id: 13566814 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id E0A7FC48BF8 for ; Thu, 22 Feb 2024 07:46:41 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 49FB510E893; Thu, 22 Feb 2024 07:46:41 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="aQ3CvQz1"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.18]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9818910E898 for ; Thu, 22 Feb 2024 07:46:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1708587985; x=1740123985; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=43oSwD68BJ58wAq9sS8fi5WA+e8nJuyUV1lh1RDewpE=; b=aQ3CvQz1dQX2oM7K4fhZ4q54xB/57QZOTRee7UTyJDqfsWQEPGb9mL5m 7Klqf4n8W4zOLFgwdBZ9JyJsqLHNAqoFiOgcNXM/Ui+U1HgK9NYjcIjC8 JR4rYoLkU9dRquDsulBsaAUELQMXHgZSLrWp0le2TH8Z8BiQDWuHJCt6f Mm2hGlySocStYA7kjIWmB/6I9ltWQ6gqWnLaUtaiQ8Yox19fvRO7K2+lu glaPOR8RG+cjHsjVOZJiPf83cRp2suB7MnhLQiWYQrMukRm9/lLeHHdvt pS7N8mO1EDymdcgHdbct0ydxO0UdoPsMgrUeQLPY3ER20a3s/PcXVE+cJ g==; X-IronPort-AV: E=McAfee;i="6600,9927,10991"; a="2906069" X-IronPort-AV: E=Sophos;i="6.06,177,1705392000"; d="scan'208";a="2906069" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by orvoesa110.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Feb 2024 23:46:18 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.06,177,1705392000"; d="scan'208";a="5354183" Received: from kandpal-x299-ud4-pro.iind.intel.com ([10.190.239.32]) by fmviesa009.fm.intel.com with ESMTP; 21 Feb 2024 23:46:17 -0800 From: Suraj Kandpal To: intel-gfx@lists.freedesktop.org Cc: uma.shankar@intel.com, ankit.k.nautiyal@intel.com, Suraj Kandpal Subject: [PATCH 13/13] drm/i915/hdcp: Read Rxcaps for robustibility Date: Thu, 22 Feb 2024 13:13:54 +0530 Message-ID: <20240222074353.1568904-15-suraj.kandpal@intel.com> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240222074353.1568904-2-suraj.kandpal@intel.com> References: <20240222074353.1568904-2-suraj.kandpal@intel.com> MIME-Version: 1.0 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" We see some monitors and docks report incorrect hdcp version and capability in first few reads so we read rx_caps three times before we conclude the monitor's or docks HDCP capability --v2 -Add comment to justify the 3 time read loop for hdcp capability[Ankit] Signed-off-by: Suraj Kandpal Reviewed-by: Ankit Nautiyal --- drivers/gpu/drm/i915/display/intel_dp_hdcp.c | 29 ++++++++++++++------ 1 file changed, 20 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c index cedabbaaf615..5af289bbf828 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c @@ -644,18 +644,29 @@ int _intel_dp_hdcp2_get_capability(struct drm_dp_aux *aux, bool *capable) { u8 rx_caps[3]; - int ret; + int ret, i; *capable = false; - ret = drm_dp_dpcd_read(aux, - DP_HDCP_2_2_REG_RX_CAPS_OFFSET, - rx_caps, HDCP_2_2_RXCAPS_LEN); - if (ret != HDCP_2_2_RXCAPS_LEN) - return ret >= 0 ? -EIO : ret; - if (rx_caps[0] == HDCP_2_2_RX_CAPS_VERSION_VAL && - HDCP_2_2_DP_HDCP_CAPABLE(rx_caps[2])) - *capable = true; + /* + * Some HDCP monitors act really shady by not giving the correct hdcp + * capability on the first rx_caps read and usually take an extra read + * to give the capability. We read rx_caps three times before we + * declare a monitor not capable of HDCP 2.2. + */ + for (i = 0; i < 3; i++) { + ret = drm_dp_dpcd_read(aux, + DP_HDCP_2_2_REG_RX_CAPS_OFFSET, + rx_caps, HDCP_2_2_RXCAPS_LEN); + if (ret != HDCP_2_2_RXCAPS_LEN) + return ret >= 0 ? -EIO : ret; + + if (rx_caps[0] == HDCP_2_2_RX_CAPS_VERSION_VAL && + HDCP_2_2_DP_HDCP_CAPABLE(rx_caps[2])) { + *capable = true; + break; + } + } return 0; }