From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 584D5C4338F for ; Wed, 11 Aug 2021 19:34:26 +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 156B260F35 for ; Wed, 11 Aug 2021 19:34:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 156B260F35 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6063D6E1A5; Wed, 11 Aug 2021 19:34:25 +0000 (UTC) Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id BA8486E1A8; Wed, 11 Aug 2021 19:34:23 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10073"; a="276241668" X-IronPort-AV: E=Sophos;i="5.84,313,1620716400"; d="scan'208";a="276241668" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Aug 2021 12:34:22 -0700 X-IronPort-AV: E=Sophos;i="5.84,313,1620716400"; d="scan'208";a="516913845" Received: from gdthomps-mobl.amr.corp.intel.com (HELO intel.com) ([10.255.37.76]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Aug 2021 12:34:21 -0700 Date: Wed, 11 Aug 2021 15:34:20 -0400 From: Rodrigo Vivi To: Juston Li , Dave Airlie , Daniel Vetter Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, seanpaul@chromium.org, anshuman.gupta@intel.com, ramalingam.c@intel.com Message-ID: References: <20210810235212.138721-1-juston.li@intel.com> <20210810235212.138721-3-juston.li@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210810235212.138721-3-juston.li@intel.com> Subject: Re: [Intel-gfx] [PATCH v3 2/3] drm/i915/hdcp: read RxInfo once when reading RepeaterAuth_Send_ReceiverID_List 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: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Tue, Aug 10, 2021 at 04:52:11PM -0700, Juston Li wrote: > When reading RepeaterAuth_Send_ReceiverID_List, RxInfo is read by itself > once to retrieve the DEVICE_COUNT to calculate the size of the > ReceiverID list then read a second time as a part of reading ReceiverID > list. > > On some MST docking stations, RxInfo can only be read after the RxStatus > READY bit is set otherwise the read will return -EIO. The spec states that > the READY bit should be cleared as soon as RxInfo has been read. > > In this case, the first RxInfo read succeeds but after the READY bit is > cleared, the second read fails. > > Fix it by reading RxInfo once and storing it before reading the rest of > RepeaterAuth_Send_ReceiverID_List once we know the size. > > Modify get_receiver_id_list_size() to read and store RxInfo in the > message buffer and also parse DEVICE_COUNT so we know the size of > RepeaterAuth_Send_ReceiverID_List. > > Afterwards, retrieve the rest of the message at the offset for > seq_num_V. > > Changes in v4: > - rebase and edit commit message > > Changes in v3: > - remove comment > > Changes in v2: > - remove unnecessary moving of drm_i915_private from patch 1 > > Signed-off-by: Juston Li > Acked-by: Anshuman Gupta > --- > drivers/gpu/drm/i915/display/intel_dp_hdcp.c | 30 ++++++++++---------- > include/drm/drm_dp_helper.h | 2 +- > 2 files changed, 16 insertions(+), 16 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c > index 1d0096654776..526fd58b9b51 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c > @@ -496,11 +496,10 @@ get_rxinfo_hdcp_1_dev_downstream(struct intel_digital_port *dig_port, bool *hdcp > } > > static > -ssize_t get_receiver_id_list_size(struct intel_digital_port *dig_port) > +ssize_t get_receiver_id_list_rx_info(struct intel_digital_port *dig_port, u32 *dev_cnt, u8 *byte) > { > - u8 rx_info[HDCP_2_2_RXINFO_LEN]; > - u32 dev_cnt; > ssize_t ret; > + u8 *rx_info = byte; > > ret = drm_dp_dpcd_read(&dig_port->dp.aux, > DP_HDCP_2_2_REG_RXINFO_OFFSET, > @@ -508,15 +507,11 @@ ssize_t get_receiver_id_list_size(struct intel_digital_port *dig_port) > if (ret != HDCP_2_2_RXINFO_LEN) > return ret >= 0 ? -EIO : ret; > > - dev_cnt = (HDCP_2_2_DEV_COUNT_HI(rx_info[0]) << 4 | > + *dev_cnt = (HDCP_2_2_DEV_COUNT_HI(rx_info[0]) << 4 | > HDCP_2_2_DEV_COUNT_LO(rx_info[1])); > > - if (dev_cnt > HDCP_2_2_MAX_DEVICE_COUNT) > - dev_cnt = HDCP_2_2_MAX_DEVICE_COUNT; > - > - ret = sizeof(struct hdcp2_rep_send_receiverid_list) - > - HDCP_2_2_RECEIVER_IDS_MAX_LEN + > - (dev_cnt * HDCP_2_2_RECEIVER_ID_LEN); > + if (*dev_cnt > HDCP_2_2_MAX_DEVICE_COUNT) > + *dev_cnt = HDCP_2_2_MAX_DEVICE_COUNT; > > return ret; > } > @@ -534,6 +529,7 @@ int intel_dp_hdcp2_read_msg(struct intel_digital_port *dig_port, > const struct hdcp2_dp_msg_data *hdcp2_msg_data; > ktime_t msg_end = ktime_set(0, 0); > bool msg_expired; > + u32 dev_cnt; > > hdcp2_msg_data = get_hdcp2_dp_msg_data(msg_id); > if (!hdcp2_msg_data) > @@ -546,17 +542,21 @@ int intel_dp_hdcp2_read_msg(struct intel_digital_port *dig_port, > > hdcp->cp_irq_count_cached = atomic_read(&hdcp->cp_irq_count); > > + /* DP adaptation msgs has no msg_id */ > + byte++; > + > if (msg_id == HDCP_2_2_REP_SEND_RECVID_LIST) { > - ret = get_receiver_id_list_size(dig_port); > + ret = get_receiver_id_list_rx_info(dig_port, &dev_cnt, byte); > if (ret < 0) > return ret; > > - size = ret; > + byte += ret; > + size = sizeof(struct hdcp2_rep_send_receiverid_list) - > + HDCP_2_2_RXINFO_LEN - HDCP_2_2_RECEIVER_IDS_MAX_LEN + > + (dev_cnt * HDCP_2_2_RECEIVER_ID_LEN); > } > - bytes_to_recv = size - 1; > > - /* DP adaptation msgs has no msg_id */ > - byte++; > + bytes_to_recv = size - 1; > > while (bytes_to_recv) { > len = bytes_to_recv > DP_AUX_MAX_PAYLOAD_BYTES ? > diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h I was about to merge to drm-intel-next but then I noticed this.. So we need to cc Dave and Daniel here to get an ack from them. > index 3f2715eb965f..7476e7c6d0be 100644 > --- a/include/drm/drm_dp_helper.h > +++ b/include/drm/drm_dp_helper.h > @@ -1413,7 +1413,7 @@ enum drm_dp_phy { > #define DP_HDCP_2_2_LC_INIT_OFFSET DP_HDCP_2_2_REG_RN_OFFSET > #define DP_HDCP_2_2_LC_SEND_LPRIME_OFFSET DP_HDCP_2_2_REG_LPRIME_OFFSET > #define DP_HDCP_2_2_SKE_SEND_EKS_OFFSET DP_HDCP_2_2_REG_EDKEY_KS_OFFSET > -#define DP_HDCP_2_2_REP_SEND_RECVID_LIST_OFFSET DP_HDCP_2_2_REG_RXINFO_OFFSET > +#define DP_HDCP_2_2_REP_SEND_RECVID_LIST_OFFSET DP_HDCP_2_2_REG_SEQ_NUM_V_OFFSET I'm not familiar with this so I'm not sure if this should be a separated patch or better explained in the commit message. Dave/Daniel how do you prefer this? > #define DP_HDCP_2_2_REP_SEND_ACK_OFFSET DP_HDCP_2_2_REG_V_OFFSET > #define DP_HDCP_2_2_REP_STREAM_MANAGE_OFFSET DP_HDCP_2_2_REG_SEQ_NUM_M_OFFSET > #define DP_HDCP_2_2_REP_STREAM_READY_OFFSET DP_HDCP_2_2_REG_MPRIME_OFFSET > -- > 2.31.1 >