From patchwork Mon Feb 26 06:30:52 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kandpal, Suraj" X-Patchwork-Id: 13571332 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 2CCD8C5478C for ; Mon, 26 Feb 2024 06:33:12 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9237010EEBC; Mon, 26 Feb 2024 06:33:11 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="A2DjjS+/"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.14]) by gabe.freedesktop.org (Postfix) with ESMTPS id D812E10EEB9 for ; Mon, 26 Feb 2024 06:33:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1708929181; x=1740465181; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=otMQcpHt4TJ8hpp6yotu/VAlbHUTbS81LGVeHsmCor0=; b=A2DjjS+/EpXw6YEMQEVjulT0rRVOhsQJytydccFCFLmeD/VoWatX6fW9 mPowebvY8r7WM+Bb30Svh3Oa00qAH0qbYbtykB1d2mmuhPe1tzsLliAG8 K9ScSKbkz4mnZOK+IDEIo9qyXM/I8Bf1+tZ/5tf4qXdFTlLzUoL+52ljv BsfsQQSiOpv4msy81W0nJZtctT3eQUu62wxf4qQJ2+xQocN7PmPZ+W6q3 gSMdbQCHh7un2ROE4JQqQ9lhv/zg2VaqOR6//5/K9du5WL3sfFuHuVo31 Y2LiqeaEvuuKuygMZ2bwV2F4ktG+il/XUjekqYWAcvxhxqSkPkagOjmdl w==; X-IronPort-AV: E=McAfee;i="6600,9927,10995"; a="3361044" X-IronPort-AV: E=Sophos;i="6.06,185,1705392000"; d="scan'208";a="3361044" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by fmvoesa108.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Feb 2024 22:33:00 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.06,185,1705392000"; d="scan'208";a="6565448" Received: from kandpal-x299-ud4-pro.iind.intel.com ([10.190.239.32]) by orviesa010.jf.intel.com with ESMTP; 25 Feb 2024 22:32:59 -0800 From: Suraj Kandpal To: intel-gfx@lists.freedesktop.org Cc: uma.shankar@intel.com, ankit.k.nautiyal@intel.com, Suraj Kandpal Subject: [PATCH 5/5] drm/i915/hdcp: Read Rxcaps for robustibility Date: Mon, 26 Feb 2024 12:00:52 +0530 Message-ID: <20240226063051.1685326-7-suraj.kandpal@intel.com> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240226063051.1685326-2-suraj.kandpal@intel.com> References: <20240226063051.1685326-2-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 99220f970039..b98a87883fef 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; }