From patchwork Thu Mar 5 20:12:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sean Paul X-Patchwork-Id: 11422547 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 DD2A792A for ; Thu, 5 Mar 2020 20:13:01 +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 BBBA2207FD for ; Thu, 5 Mar 2020 20:13:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=poorly.run header.i=@poorly.run header.b="WzmoRSyg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BBBA2207FD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=poorly.run Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C7DF56EC1C; Thu, 5 Mar 2020 20:12:46 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mail-yw1-xc41.google.com (mail-yw1-xc41.google.com [IPv6:2607:f8b0:4864:20::c41]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3B1256EC12 for ; Thu, 5 Mar 2020 20:12:43 +0000 (UTC) Received: by mail-yw1-xc41.google.com with SMTP id p124so2997583ywc.8 for ; Thu, 05 Mar 2020 12:12:43 -0800 (PST) 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=X1YqvBKqg7/VryAOK9RwH9BwHNsCXx8VTJSjh1czkIs=; b=WzmoRSygBRqtMF2E4liPFh4tPPyi4/X+gij40jjbnQGdpI7tnDsPZPwelNWSI11FFt ONllhwj38ovOW7Z58Nw+Bxg0Y+Kh8g6gZXAz6OsyQNIDNDdxuallgTh2WhdP6XwOE7hT gPNsDDVlh/c9W1BnaoTuaWZ5WuiPy/DE28dqxLPvu5C4qj1rqQdTlRzo/pBP/PQcjMhj 5dR2KAKWsdKWZT+VkbVCKvfzSc9X1fWWb6VvjavVlClHTwQ7xOfLFFdtvzKYeNGS1Ioz i+KNiX0D2tIbmr6AnVkd8l/J1puamjZXEc0cLCdJRuwZcR8JB96tVI9dWHC/RziJUPQK wFyQ== 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=X1YqvBKqg7/VryAOK9RwH9BwHNsCXx8VTJSjh1czkIs=; b=a5zw5wNPNQTIuawy2TCruigs0lzH1k+W5S0tTBtnJ6iwR1o104+hOwdKZOMkZgesl8 +EtMHQN82h3EbHZuQyOII7tek8AXM2VLJgnHrUBpMezKlw9SIZzym8C4liAPIx7gHnBm VBCCrnnbtj33bvh3smAiSQqhL5Du2VEMudwaLYfHBKyoY2Jpym6WC5j4jX1oxry+kRds 6VBRlgSsY5nq6qd4W+eSOzurZDGF6C/Y55HJ+JbLWxK7QjN2M97dG2m9yOPjprmRPd7v D10FHoWsIn6TUaxBasHlx5MoZhxYeDNnDyqU0MmAtAWhXapKcxr38rxZ8yxbFn+MviaE 3fCg== X-Gm-Message-State: ANhLgQ0x27ok8p/WXDR2VHPK1/1MZO5PeJnr/aksyT85PKEKQjaUkKqh IN2Hza8jXnNxnyL9TfkRnsnjSw== X-Google-Smtp-Source: ADFU+vuu3V2zZ8MmnIYrKOdrjJctybwN1t7BQPqknIdWWLBncyI3sTtUFzI+aL5HSlmkGd4WqdwKDw== X-Received: by 2002:a25:9390:: with SMTP id a16mr9026054ybm.189.1583439162412; Thu, 05 Mar 2020 12:12:42 -0800 (PST) Received: from localhost ([2620:0:1013:11:1e1:4760:6ce4:fc64]) by smtp.gmail.com with ESMTPSA id w132sm12523793ywc.51.2020.03.05.12.12.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Mar 2020 12:12:42 -0800 (PST) From: Sean Paul To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Date: Thu, 5 Mar 2020 15:12:24 -0500 Message-Id: <20200305201236.152307-5-sean@poorly.run> X-Mailer: git-send-email 2.25.1.481.gfbce0eb801-goog In-Reply-To: <20200305201236.152307-1-sean@poorly.run> References: <20200305201236.152307-1-sean@poorly.run> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v5 04/16] drm/i915: Intercept Aksv writes in the aux hooks 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: , Cc: daniel.vetter@ffwll.ch, Sean Paul Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" 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. Reviewed-by: Ville Syrjälä Reviewed-by: Ramalingam C Signed-off-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20191203173638.94919-3-sean@poorly.run #v1 Link: https://patchwork.freedesktop.org/patch/msgid/20191212190230.188505-5-sean@poorly.run #v2 Link: https://patchwork.freedesktop.org/patch/msgid/20200117193103.156821-5-sean@poorly.run #v3 Link: https://patchwork.freedesktop.org/patch/msgid/20200218220242.107265-5-sean@poorly.run #v4 Changes in v2: -Remove 'generate' in intel_dp_aux_generate_xfer_flags, make arg const (Ville) -Bundle Aksv if statement together (Ville) -Rename 'txbuf' to 'aksv' (Ville) Changes in v3: -None Changes in v4: -None Changes in v5: -None --- drivers/gpu/drm/i915/display/intel_dp.c | 62 ++++++++++++------------- 1 file changed, 29 insertions(+), 33 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 0a417cd2af2bc..1f80a1244abbb 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -1534,12 +1534,27 @@ intel_dp_aux_header(u8 txbuf[HEADER_SIZE], txbuf[3] = msg->size - 1; } +static u32 intel_dp_aux_xfer_flags(const struct drm_dp_aux_msg *msg) +{ + /* + * 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->request & ~DP_AUX_I2C_MOT) == DP_AUX_NATIVE_WRITE && + 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_xfer_flags(msg); int ret; intel_dp_aux_header(txbuf, msg); @@ -1560,7 +1575,7 @@ 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; @@ -1583,7 +1598,7 @@ 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; /* @@ -5959,17 +5974,9 @@ 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(to_intel_encoder(&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 aksv[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) { @@ -5979,29 +5986,18 @@ 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, + aksv, 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; }