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=-15.2 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,USER_AGENT_SANE_1 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 49CEBC4338F for ; Thu, 12 Aug 2021 08:00:43 +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 D0A2C61038 for ; Thu, 12 Aug 2021 08:00:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D0A2C61038 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 DA5956E311; Thu, 12 Aug 2021 08:00:41 +0000 (UTC) Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7CC7F6E0EF for ; Thu, 12 Aug 2021 08:00:32 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10073"; a="215330442" X-IronPort-AV: E=Sophos;i="5.84,315,1620716400"; d="scan'208";a="215330442" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Aug 2021 01:00:21 -0700 X-IronPort-AV: E=Sophos;i="5.84,315,1620716400"; d="scan'208";a="590550469" Received: from genxfsim-desktop.iind.intel.com (HELO intel.com) ([10.223.74.179]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Aug 2021 01:00:18 -0700 Date: Thu, 12 Aug 2021 13:13:04 +0530 From: Anshuman Gupta To: Juston Li Cc: intel-gfx@lists.freedesktop.org, seanpaul@chromium.org, ramalingam.c@intel.com, rodrigo.vivi@intel.com Message-ID: <20210812074303.GC814@intel.com> References: <20210811212314.153269-1-juston.li@intel.com> <20210811212314.153269-3-juston.li@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210811212314.153269-3-juston.li@intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) Subject: Re: [Intel-gfx] [PATCH v4 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 2021-08-11 at 14:23:13 -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 v5: > - Don't change the offset define for Send_ReceiverID_List > When reading, update message offset to account for RxInfo being read v5 looks good to me Reviewed-by: Anshuman Gupta > > 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 > Reviewed-by: Ramalingam C > --- > drivers/gpu/drm/i915/display/intel_dp_hdcp.c | 31 ++++++++++---------- > 1 file changed, 16 insertions(+), 15 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..fbfb3c4d16bb 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 +542,22 @@ 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); > + offset += HDCP_2_2_RXINFO_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 ? > -- > 2.31.1 >