From patchwork Tue Jun 23 15:58:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sean Paul X-Patchwork-Id: 11620971 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 D4C9C13B1 for ; Tue, 23 Jun 2020 15:59:30 +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 B2DD12078B for ; Tue, 23 Jun 2020 15:59:30 +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="CngBr3/T" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B2DD12078B 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 AAA796E9D7; Tue, 23 Jun 2020 15:59:25 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail-qt1-x843.google.com (mail-qt1-x843.google.com [IPv6:2607:f8b0:4864:20::843]) by gabe.freedesktop.org (Postfix) with ESMTPS id F164F6E9DA for ; Tue, 23 Jun 2020 15:59:22 +0000 (UTC) Received: by mail-qt1-x843.google.com with SMTP id i3so6265575qtq.13 for ; Tue, 23 Jun 2020 08:59:22 -0700 (PDT) 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=SdwvzvBkkWPhqvHSgLulH/jLQ2ULchQPrd2y/w2tfFA=; b=CngBr3/TC0P05qqfkW62uQw89/F1dRmlSY8UbY8m1pSOTB248o9nQrQS6Z0VZnOuM5 LOsSYi9qOrPxogob+BFbHCqf21Qr7HibeODIWvwL+J2NQRA6ZKldjHhGgL3c1PxMIe6r RWLOp39mXUHr16kDr9U5y9zwvosuTIgpcaqZor8/VnSLnZ/4wSG3Eu4cAD7X7Qa4QO2l R1tNhO6PEuRYa2gRpQPOLVOcLqRhOGB+u/tN/0gquQAGMZlnM+yOpFUXXB1hH7zoJ01j 1zHk6pdnuUyo6JbB25/UGT3P+6soUwnFSmRly2zech2GTjac3ZbQEP1yJf8ubMsUY3j1 Dvcg== 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=SdwvzvBkkWPhqvHSgLulH/jLQ2ULchQPrd2y/w2tfFA=; b=CdXzsGXtjLiIajpaDiry7WhL15GFhb2L5JqmxvDOOnwNlHe7HOC2cPs7bqSUowV95o 5Cu1qVljGR97NIPmCAizpKWlVhsxM9iT9TwQEglLXj5vKnGYwNI14ZEbrPUTndVqcB2V lBThvzbDid/ope5W28GIi53Pqva2pausiJp0hssFo8iNRmKQntZCliAGH+CdbSVg/Jcc Y68MN2pjmHmFEmNhDwgQkZB2WVlIT5PvGCc57SiT6Lzb2BBLmPRiA5NX8Bns8TrdX7LU pAhrpsJgzEfiyhV9oaEDqanIm7Em6vl7B9MAZgq2WH6ud+hZGwFwrTfVHtvzqYtgFMPb KLgw== X-Gm-Message-State: AOAM53322T+7ZQ46rItSb7w5je4rf41qj4LkqFryl2ysDZAb5TFlQkiL +zmwS2n+Qz6cAq6KFiMdrmwck9LcHhw= X-Google-Smtp-Source: ABdhPJya3O0F2iJcc+H5fwEelHN07jRcHwmOOhyxkrULpGNxpWcyMSyDtQIk2J4ohgh74SPS+vvPNw== X-Received: by 2002:ac8:2928:: with SMTP id y37mr22430732qty.245.1592927961820; Tue, 23 Jun 2020 08:59:21 -0700 (PDT) Received: from localhost ([166.137.96.174]) by smtp.gmail.com with ESMTPSA id k14sm925727qtm.38.2020.06.23.08.59.21 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Tue, 23 Jun 2020 08:59:21 -0700 (PDT) From: Sean Paul To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Subject: [PATCH v7 04/17] drm/i915: Intercept Aksv writes in the aux hooks Date: Tue, 23 Jun 2020 11:58:54 -0400 Message-Id: <20200623155907.22961-5-sean@poorly.run> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200623155907.22961-1-sean@poorly.run> References: <20200623155907.22961-1-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, Sean Paul , juston.li@intel.com, rodrigo.vivi@intel.com 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 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 Link: https://patchwork.freedesktop.org/patch/msgid/20200305201236.152307-5-sean@poorly.run #v5 Link: https://patchwork.freedesktop.org/patch/msgid/20200429195502.39919-5-sean@poorly.run #v6 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 Changes in v6: -None Changes in v7: -None --- drivers/gpu/drm/i915/display/intel_dp.c | 63 ++++++++++++------------- 1 file changed, 29 insertions(+), 34 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 3df5d901dd9d..b30846e9e634 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -1563,6 +1563,20 @@ 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) { @@ -1570,6 +1584,7 @@ intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) struct drm_i915_private *i915 = dp_to_i915(intel_dp); 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); @@ -1590,7 +1605,7 @@ 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; @@ -1613,7 +1628,7 @@ 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; /* @@ -6398,17 +6413,9 @@ int intel_dp_hdcp_write_an_aksv(struct intel_digital_port *intel_dig_port, u8 *an) { struct drm_i915_private *i915 = to_i915(intel_dig_port->base.base.dev); - 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) { @@ -6419,31 +6426,19 @@ 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_dbg_kms(&i915->drm, - "Write Aksv over DP/AUX failed (%d)\n", ret); - return ret; - } else if (ret == 0) { - drm_dbg_kms(&i915->drm, "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) { + 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_dbg_kms(&i915->drm, - "Aksv write: no DP_AUX_NATIVE_REPLY_ACK %x\n", - reply); - return -EIO; + "Failed to write Aksv over DP/AUX (%zd)\n", + dpcd_ret); + return dpcd_ret >= 0 ? -EIO : dpcd_ret; } return 0; }