From patchwork Tue Aug 18 15:38:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sean Paul X-Patchwork-Id: 11721713 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 B7974722 for ; Tue, 18 Aug 2020 15:39:49 +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 9613C20829 for ; Tue, 18 Aug 2020 15:39:49 +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="OAK4/3RZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9613C20829 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 9078D89F6F; Tue, 18 Aug 2020 15:39:48 +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 B0A9B89CF5 for ; Tue, 18 Aug 2020 15:39:47 +0000 (UTC) Received: by mail-qt1-x843.google.com with SMTP id t23so15444196qto.3 for ; Tue, 18 Aug 2020 08:39:47 -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=PW7HIpyWQg5K2h8LaCsx6dGixv2bzhbpg6dSNdBDdPo=; b=OAK4/3RZ3NWFBqNx0nzH+t0BgCoxzOmcLgI7lc8AnOzXloLhrddW0p3U89svCDianU us3pN2zB5AwiUHEmSBMcEpTZ+zgWLaKZJUFNibuUHLWlnUZ6d0v+KWvFZ1eYttjZwNA2 47kEGJWDFcm0bdBwfvHllhl9n4zxaLRYPoqb1rSB+i3IQZ8suIJR1GRQiJwTL2Oqlj9r 6zOlnVBblNZb+8O11ifVWX5RTRwEzgkvw+pWBlHhYcREifrM2wOXX71jEYWO/WDn9ZrI 1mcf1WaAdFFp9D/2kDER7kZVdzwHPI8UD0b5k7N59MmudTYbN+m6eH/hcB81RLEAcnOt G43Q== 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=PW7HIpyWQg5K2h8LaCsx6dGixv2bzhbpg6dSNdBDdPo=; b=OzYWbyOmMRjaaDnsduER+4cD1ZrVjMy+odV5X+ozMEeN3VDIIZE4jNBM72YRSl/kIn h7qOS3FN/Y5c/r2DZ4oZqBu28LQGU5xQ4zY2ah2SFfHfnmwhLK5sueOZUnX7qDguicXf vhpeBbjC9KlxhgYnG5PT9CkirZs1TR7E5+l3xu4FhE2KTMcyLyfKv9P4OmOi75xNfVjL MMx/iWg8CM1IyvHK8cHgLviL4+A6HQ/8XD5mzUtTtlYjFy5RhAuatN3Z6DfkbC8BhUKd RwLxdNH7KMEuY8nX8r+ciXO+0y4lP2UtokOI53e5zf+QNtjmlOz4kckAPYJHFvrEFSU1 Gx5w== X-Gm-Message-State: AOAM533DDb0LPMGOi+C0vc3fBkBYorXejwMOtx1Vau0aTueirM56EmTA HrvfNFPAyrO/6vhXAZykzBNEdf7+BqRP8w== X-Google-Smtp-Source: ABdhPJw9SFg6Pj/Vj83HxI4NeGDU9s6o9Df91EZMLgjYklGC0jrzMvpGR8LNz05q8gngVDJCwh7joQ== X-Received: by 2002:ac8:776b:: with SMTP id h11mr18266679qtu.59.1597765186564; Tue, 18 Aug 2020 08:39:46 -0700 (PDT) Received: from localhost (mobile-166-170-57-144.mycingular.net. [166.170.57.144]) by smtp.gmail.com with ESMTPSA id t12sm20268101qkt.56.2020.08.18.08.39.45 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Tue, 18 Aug 2020 08:39:46 -0700 (PDT) From: Sean Paul To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, juston.li@intel.com, jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com, anshuman.gupta@intel.com Subject: [PATCH v8 04/17] drm/i915: Intercept Aksv writes in the aux hooks Date: Tue, 18 Aug 2020 11:38:52 -0400 Message-Id: <20200818153910.27894-5-sean@poorly.run> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200818153910.27894-1-sean@poorly.run> References: <20200818153910.27894-1-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: David Airlie , daniel.vetter@ffwll.ch, 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 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 Link: https://patchwork.freedesktop.org/patch/msgid/20200623155907.22961-5-sean@poorly.run #v7 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 Changes in v8: -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 79c27f91f42c..7d1774bfbe41 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; /* @@ -6403,15 +6418,8 @@ int intel_dp_hdcp_write_an_aksv(struct intel_digital_port *dig_port, u8 *an) { struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev); - struct intel_dp *intel_dp = enc_to_intel_dp(to_intel_encoder(&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(&dig_port->dp.aux, DP_AUX_HDCP_AN, @@ -6424,31 +6432,19 @@ int intel_dp_hdcp_write_an_aksv(struct intel_digital_port *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(&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; }