From patchwork Thu Feb 15 05:05:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kandpal, Suraj" X-Patchwork-Id: 13557375 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 50A57C48BC4 for ; Thu, 15 Feb 2024 05:07:53 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A95A510E1AE; Thu, 15 Feb 2024 05:07:52 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="mjJvCjQH"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.15]) by gabe.freedesktop.org (Postfix) with ESMTPS id 50D8410E1C7 for ; Thu, 15 Feb 2024 05:07:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1707973671; x=1739509671; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=4qUDDQF9dCnxdYZvi+SDVdVbzlAqs5/wLR5x0DsZMm0=; b=mjJvCjQH9EujLdFcL/nA2rNjsi9frit+yhGBXUbTDd3zdzSeedvsRE1X Bqh40iOiOkE4blSZ+GYALxwj0zOFmZVAqRysum41+Yj2XJQ8ydY+gwkuc RUhtQH7UrDBayIyI2CuJWQrDEME8+U4Afvo1SoH2RozAp1jgkrCRTsfqq 5yYQoQX/uS5aCXv66TAlEWl+6yEzWYDdYu+U//5fz4m/9QaBBTKZ4B28h GnSKBqQVAFCEX5G52KAkdhVoSEX9wDiyg3qsSUrG24wX5nR95hsuA/5Ul BPIukVquYx+UDb9PxG3dFHFli9yywMskDXwC0sVGuCR/O49qdSYaTFuGz A==; X-IronPort-AV: E=McAfee;i="6600,9927,10984"; a="5877255" X-IronPort-AV: E=Sophos;i="6.06,161,1705392000"; d="scan'208";a="5877255" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Feb 2024 21:07:50 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.06,161,1705392000"; d="scan'208";a="8084204" Received: from kandpal-x299-ud4-pro.iind.intel.com ([10.190.239.32]) by orviesa003.jf.intel.com with ESMTP; 14 Feb 2024 21:07:48 -0800 From: Suraj Kandpal To: intel-gfx@lists.freedesktop.org Cc: jani.nikula@intel.com, uma.shankar@intel.com, ankit.k.nautiyal@intel.com, Suraj Kandpal Subject: [PATCH 12/12] drm/i915/hdcp: Read Rxcaps for robustibility Date: Thu, 15 Feb 2024 10:35:24 +0530 Message-Id: <20240215050524.1425206-13-suraj.kandpal@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240215050524.1425206-1-suraj.kandpal@intel.com> References: <20240215050524.1425206-1-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 ed7afde417bc..bddc2e5f329e 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c @@ -640,18 +640,29 @@ 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; }