From patchwork Fri Jan 17 19:30:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sean Paul X-Patchwork-Id: 11339661 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 A05A4921 for ; Fri, 17 Jan 2020 19:31:28 +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 7F3132072B for ; Fri, 17 Jan 2020 19:31:28 +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="WDo/jNCz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7F3132072B 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 27DC76F8E1; Fri, 17 Jan 2020 19:31:15 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail-yw1-xc43.google.com (mail-yw1-xc43.google.com [IPv6:2607:f8b0:4864:20::c43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 671D36F8DA for ; Fri, 17 Jan 2020 19:31:11 +0000 (UTC) Received: by mail-yw1-xc43.google.com with SMTP id b186so14850871ywc.1 for ; Fri, 17 Jan 2020 11:31:11 -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=SbNgaMiTiOnuP5x7gX1mRS5vhRHmZZDgtqKGI/95uUY=; b=WDo/jNCzpIjteT6slJO5OAxoOx1qm5KozHFnrFFef8CXsmZeQ8/NzzQzP86Pg8RQv3 nbpf8kRUsCOtku0xitylysA7Sgg6KsgbYSMQZaaBR7qHIxY9efXwUbARg8r3TtOLa0Zo EbMnl5QF2fXO7Z6NQNur03TXI71gkPIdOgeJrkwjNv2/7fKEqNYmg/MPtr4N+NlJJvw8 pFUeFQscDQ1kKj2+JbvKIsOgU8TukPPWPHHUzJSaT0Q6X6WHgtEd3U0v59nr3EQduyee L+yek8MCoZCIep8+ENfiRj9g0lPgMHV/EUoLTDPAs91RUgx4PTSRPystlCmWAwjcgoO0 aX9g== 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=SbNgaMiTiOnuP5x7gX1mRS5vhRHmZZDgtqKGI/95uUY=; b=d08Glb3nDcnIGK1XHBwhzCS8TehLuh0UDLu349SLZUTWdo4DUCIyJurnWB2TmA31Io Lg8spKJCaRRzgo8WJEkU8g9vNsWw3TTwe55WrKijgYNWsrKdMaoGjRJ4RF/8aqMjFcbm eslNWnqwUrWwKlkxRu5aGV2C91lhUpZKCYhuRfN7pIzicDtskS26toC2xDGdnUVA1au4 uxdl9nru8my9eHz809TF2520ZSP4sC1oisV87cQb50Rfn4cuhZLhKba2PfgU3l1YwFNu s8UxBMAmCmEeWfgRAE9PLu09lvL6ufNbBYd4MX81dBnTzpNwnXF5KvVArLXu3cd06MO7 QPDA== X-Gm-Message-State: APjAAAW8H7EEs/FtG+AHfr4c1WjRD8bgIIcc/iN6lFX4T9Bm0B8uKmwr yhToNd0nWeKxbjK6Ys1iCIExWC/kt1RjjA== X-Google-Smtp-Source: APXvYqz/yCMJFOzlADix9RzmgcLqjA4WjrMIrzaDFEcrlxiX+WzFCHmyro9a55/oNZRLKFaoya3slw== X-Received: by 2002:a81:6f07:: with SMTP id k7mr33628147ywc.395.1579289470209; Fri, 17 Jan 2020 11:31:10 -0800 (PST) Received: from localhost ([2620:0:1013:11:1e1:4760:6ce4:fc64]) by smtp.gmail.com with ESMTPSA id y9sm11248970ywc.19.2020.01.17.11.31.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Jan 2020 11:31:09 -0800 (PST) From: Sean Paul To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Subject: [PATCH v3 04/12] drm/i915: Intercept Aksv writes in the aux hooks Date: Fri, 17 Jan 2020 14:30:55 -0500 Message-Id: <20200117193103.156821-5-sean@poorly.run> X-Mailer: git-send-email 2.25.0.341.g760bfbb309-goog In-Reply-To: <20200117193103.156821-1-sean@poorly.run> References: <20200117193103.156821-1-sean@poorly.run> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: daniel.vetter@ffwll.ch, rodrigo.vivi@intel.com, Sean Paul 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. 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 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 --- 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 4074d83b1a5f..0d59f62917ed 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -1515,12 +1515,27 @@ 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); @@ -1541,7 +1556,7 @@ 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 +1579,7 @@ 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; /* @@ -5904,17 +5919,9 @@ 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) { @@ -5924,29 +5931,18 @@ 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; }