From patchwork Tue Dec 3 17:36:25 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sean Paul X-Patchwork-Id: 11271757 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 83969930 for ; Tue, 3 Dec 2019 17:37:09 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 68B012080F for ; Tue, 3 Dec 2019 17:37:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 68B012080F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=poorly.run Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9ED3E6EA37; Tue, 3 Dec 2019 17:37:08 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail-yb1-xb41.google.com (mail-yb1-xb41.google.com [IPv6:2607:f8b0:4864:20::b41]) by gabe.freedesktop.org (Postfix) with ESMTPS id F29896EA38 for ; Tue, 3 Dec 2019 17:37:06 +0000 (UTC) Received: by mail-yb1-xb41.google.com with SMTP id o22so1312513ybg.6 for ; Tue, 03 Dec 2019 09:37:06 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=X6sNlVpgJqZUTF2LBDVfN2KTo3rKVtV7s8d4MgGBrfw=; b=FjgKa1CXkhJBTMNeiEGjIwn2XjbH8VsXBshqAE1hAfriLX0BXLle/Jxm4X0/LDaRzy uMmxaR1aBUlRO4bsw4ptR9+XvAOZWpYriBeEvuOyM89hIpjNiXZsujZtVWYGNAgs6Bly h/0f6IstTr+qwtZABAT+O1RZfAsWoqjZGuqQtr08tdcBFBJP5kVacUDnfb9qfgzmvNVg z9K82MREa8evVYHHhcZ3I8hyY1P1oHuC/cR0f6QDWTF+Ib+F1clA93A+8vAQVMSsVn/w HSDmnsUNs+QEGCk25yW7M+MWLCGdjW6B1BftCic2cjbTWu7MO5uxbZgfdj28qjoo2VUS 566A== X-Gm-Message-State: APjAAAXVvzCBLIQ1vpYQpRmHVlFA2nlcYCiBBn4ldJVvD2Pb59vDFh4n h7phwSivMB9THUBDvMzRe52eYdUCNCKScg== X-Google-Smtp-Source: APXvYqwrYDr7iNgEM1SWLZi/pYA9DfnE9DJ3vVKeHlVWG0u5mpHYDQm6vWTYSGLc6nS7YrDj3ue3lw== X-Received: by 2002:a5b:443:: with SMTP id s3mr5184402ybp.197.1575394625799; Tue, 03 Dec 2019 09:37:05 -0800 (PST) Received: from rosewood.cam.corp.google.com ([2620:0:1013:11:89c6:2139:5435:371d]) by smtp.gmail.com with ESMTPSA id g190sm1729426ywf.41.2019.12.03.09.37.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Dec 2019 09:37:05 -0800 (PST) From: Sean Paul To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, ramalingm.c@intel.com Subject: [PATCH 02/11] drm/i915: Intercept Aksv writes in the aux hooks Date: Tue, 3 Dec 2019 12:36:25 -0500 Message-Id: <20191203173638.94919-3-sean@poorly.run> X-Mailer: git-send-email 2.24.0.393.g34dc348eaf-goog In-Reply-To: <20191203173638.94919-1-sean@poorly.run> References: <20191203173638.94919-1-sean@poorly.run> MIME-Version: 1.0 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=poorly.run; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=X6sNlVpgJqZUTF2LBDVfN2KTo3rKVtV7s8d4MgGBrfw=; b=RwAWrscCqcMya1X9tIqHH5wnB6nWBRFhjyTj6QmoW1RgHHI5TanAQ7YmntUOlvCdQJ 2C3uQ4QYT+s/uHX4moi9HbxNr+5x+C+JIl9fSnQ6KtgMTlbRS036FLUjdRyco4P4/qwM xFcurqbNROtmEHWq39n0O39IImvEWsJ2R83bEBt1t/an0JciM0Ej+GZkmYJMQi0LE7C8 QmPr0elj4s7pzmxmpF6GVrmy7GQnVUyxTiHb/x1t42ULA5YnOof0egnV6/6OFAkMz1DL zfHgTKuvbeN6SA4fi35i5KeMdJQqha+FMNRe4AJEw5f3Pq1I9aLSXmcKOMGXz0DuDFcI jSBg== 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: , Cc: David Airlie , Sean Paul , Rodrigo Vivi Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Sean Paul Instead of hand rolling the transfer ourselves in the hdcp hook, inspect aux messages and add the aksv flag in the aux transfer hook. IIRC, this was the original implementation and folks wanted this hack to be isolated to the hdcp code, which makes sense. However in testing an LG monitor on my desk, I noticed it was passing back a DEFER reply. This wasn't handled in our hand-rolled code and HDCP auth was failing as a result. Instead of copy/pasting all of the retry logic and delays from drm dp helpers, let's just use the helpers and hide the aksv select as best as we can. Signed-off-by: Sean Paul Reviewed-by: Ville Syrjälä --- drivers/gpu/drm/i915/display/intel_dp.c | 64 ++++++++++++------------- 1 file changed, 31 insertions(+), 33 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index d958e789ab96..7a407c651fb2 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -1515,12 +1515,29 @@ intel_dp_aux_header(u8 txbuf[HEADER_SIZE], txbuf[3] = msg->size - 1; } +static u32 intel_dp_aux_generate_xfer_flags(struct drm_dp_aux_msg *msg) +{ + if ((msg->request & ~DP_AUX_I2C_MOT) != DP_AUX_NATIVE_WRITE) + return 0; + + /* + * If we're trying to send the HDCP Aksv, we need to set a the Aksv + * select bit to inform the hardware to send the Aksv after our header + * since we can't access that data from software. + */ + if (msg->address == DP_AUX_HDCP_AKSV) + return DP_AUX_CH_CTL_AUX_AKSV_SELECT; + + return 0; +} + static ssize_t intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) { struct intel_dp *intel_dp = container_of(aux, struct intel_dp, aux); u8 txbuf[20], rxbuf[20]; size_t txsize, rxsize; + u32 flags = intel_dp_aux_generate_xfer_flags(msg); int ret; intel_dp_aux_header(txbuf, msg); @@ -1541,7 +1558,7 @@ intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) memcpy(txbuf + HEADER_SIZE, msg->buffer, msg->size); ret = intel_dp_aux_xfer(intel_dp, txbuf, txsize, - rxbuf, rxsize, 0); + rxbuf, rxsize, flags); if (ret > 0) { msg->reply = rxbuf[0] >> 4; @@ -1564,7 +1581,7 @@ intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) return -E2BIG; ret = intel_dp_aux_xfer(intel_dp, txbuf, txsize, - rxbuf, rxsize, 0); + rxbuf, rxsize, flags); if (ret > 0) { msg->reply = rxbuf[0] >> 4; /* @@ -5858,17 +5875,9 @@ static int intel_dp_hdcp_write_an_aksv(struct intel_digital_port *intel_dig_port, u8 *an) { - struct intel_dp *intel_dp = enc_to_intel_dp(&intel_dig_port->base.base); - static const struct drm_dp_aux_msg msg = { - .request = DP_AUX_NATIVE_WRITE, - .address = DP_AUX_HDCP_AKSV, - .size = DRM_HDCP_KSV_LEN, - }; - u8 txbuf[HEADER_SIZE + DRM_HDCP_KSV_LEN] = {}, rxbuf[2], reply = 0; + u8 txbuf[DRM_HDCP_KSV_LEN] = {}; ssize_t dpcd_ret; - int ret; - /* Output An first, that's easy */ dpcd_ret = drm_dp_dpcd_write(&intel_dig_port->dp.aux, DP_AUX_HDCP_AN, an, DRM_HDCP_AN_LEN); if (dpcd_ret != DRM_HDCP_AN_LEN) { @@ -5878,29 +5887,18 @@ int intel_dp_hdcp_write_an_aksv(struct intel_digital_port *intel_dig_port, } /* - * Since Aksv is Oh-So-Secret, we can't access it in software. So in - * order to get it on the wire, we need to create the AUX header as if - * we were writing the data, and then tickle the hardware to output the - * data once the header is sent out. + * Since Aksv is Oh-So-Secret, we can't access it in software. So we + * send an empty buffer of the correct length through the DP helpers. On + * the other side, in the transfer hook, we'll generate a flag based on + * the destination address which will tickle the hardware to output the + * Aksv on our behalf after the header is sent. */ - intel_dp_aux_header(txbuf, &msg); - - ret = intel_dp_aux_xfer(intel_dp, txbuf, HEADER_SIZE + msg.size, - rxbuf, sizeof(rxbuf), - DP_AUX_CH_CTL_AUX_AKSV_SELECT); - if (ret < 0) { - DRM_DEBUG_KMS("Write Aksv over DP/AUX failed (%d)\n", ret); - return ret; - } else if (ret == 0) { - DRM_DEBUG_KMS("Aksv write over DP/AUX was empty\n"); - return -EIO; - } - - reply = (rxbuf[0] >> 4) & DP_AUX_NATIVE_REPLY_MASK; - if (reply != DP_AUX_NATIVE_REPLY_ACK) { - DRM_DEBUG_KMS("Aksv write: no DP_AUX_NATIVE_REPLY_ACK %x\n", - reply); - return -EIO; + dpcd_ret = drm_dp_dpcd_write(&intel_dig_port->dp.aux, DP_AUX_HDCP_AKSV, + txbuf, DRM_HDCP_KSV_LEN); + if (dpcd_ret != DRM_HDCP_KSV_LEN) { + DRM_DEBUG_KMS("Failed to write Aksv over DP/AUX (%zd)\n", + dpcd_ret); + return dpcd_ret >= 0 ? -EIO : dpcd_ret; } return 0; }