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: 11339657 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 59AE392A for ; Fri, 17 Jan 2020 19:31:26 +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 388082072B for ; Fri, 17 Jan 2020 19:31:26 +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 388082072B 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 1880E6F8D9; Fri, 17 Jan 2020 19:31:12 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mail-yw1-xc44.google.com (mail-yw1-xc44.google.com [IPv6:2607:f8b0:4864:20::c44]) by gabe.freedesktop.org (Postfix) with ESMTPS id 102436F8DA for ; Fri, 17 Jan 2020 19:31:11 +0000 (UTC) Received: by mail-yw1-xc44.google.com with SMTP id i190so14863614ywc.2 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=XcW9jlSbRYQc4VyLIVz5kdyZGHOltxkWICJnz/f597Epbu064hVL31Iw4f9XXYMJTQ 8LWTZeNavmdbNW/tQ1JKitOCGotZv5/JjYD8JqZCAbKEaLTQ4UCyVaMLye7UM/Cq0sSH IigaA9nL2sixPflplxaCQmMSbMlvrv+hdgOPIex5Yaj1C7ANT31uEt4YHiPDlFiedmnf IQbQ0/aX/v0KDXGgH+GOH17cL/wPZsb/TLP9mACMHkBi9pEOLqESGDXENnb2x9CUYwco F9zR2VIK3jj1BJ6BZ8WAPhH3DuoTKz2X1qAtKM79vTyBex27svqEKMq1g5S7p71djMa1 V4Og== X-Gm-Message-State: APjAAAXiniUF9jmbC3tCFaUkCoI+sqrLEqtD7KayV6ERaJPWmk4KLw8y U1ACl1Hc6U9SQMEBlneXTZOriA== 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 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 Subject: [Intel-gfx] [PATCH v3 04/12] 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 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; }