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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 33404C169C4 for ; Tue, 29 Jan 2019 15:01:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0097F21848 for ; Tue, 29 Jan 2019 15:01:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727863AbfA2PBs (ORCPT ); Tue, 29 Jan 2019 10:01:48 -0500 Received: from mga12.intel.com ([192.55.52.136]:8099 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725811AbfA2PBr (ORCPT ); Tue, 29 Jan 2019 10:01:47 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Jan 2019 07:01:47 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,537,1539673200"; d="scan'208";a="314531707" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga006.fm.intel.com with ESMTP; 29 Jan 2019 07:01:45 -0800 Received: by black.fi.intel.com (Postfix, from userid 1001) id 525DF377; Tue, 29 Jan 2019 17:01:44 +0200 (EET) From: Mika Westerberg To: linux-kernel@vger.kernel.org Cc: Michael Jamet , Yehezkel Bernat , Andreas Noever , Lukas Wunner , "David S . Miller" , Mika Westerberg , Andy Shevchenko , netdev@vger.kernel.org Subject: [PATCH 04/28] thunderbolt: Add dummy read after port capability list walk on Light Ridge Date: Tue, 29 Jan 2019 18:01:19 +0300 Message-Id: <20190129150143.12681-5-mika.westerberg@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190129150143.12681-1-mika.westerberg@linux.intel.com> References: <20190129150143.12681-1-mika.westerberg@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Light Ridge has an issue where reading the next capability pointer location in port config space the read data is not cleared. It is fine to read capabilities each after another so only thing we need to do is to make sure we issue dummy read after tb_port_find_cap() is finished to avoid the issue in next read. Signed-off-by: Mika Westerberg --- drivers/thunderbolt/cap.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/thunderbolt/cap.c b/drivers/thunderbolt/cap.c index 94a507f12b71..b7a3b62805a6 100644 --- a/drivers/thunderbolt/cap.c +++ b/drivers/thunderbolt/cap.c @@ -56,6 +56,21 @@ static int tb_port_enable_tmu(struct tb_port *port, bool enable) return tb_sw_write(sw, &value, TB_CFG_SWITCH, offset, 1); } +static void tb_port_dummy_read(struct tb_port *port) +{ + /* + * When reading from next capability pointer location in port + * config space the read data is not cleared on LR. To avoid + * reading stale data on next read perform one dummy read after + * port capabilities are walked. + */ + if (port->sw->config.device_id == PCI_DEVICE_ID_INTEL_LIGHT_RIDGE) { + u32 dummy; + + tb_port_read(port, &dummy, TB_CFG_PORT, 0, 1); + } +} + static int __tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap) { u32 offset = 1; @@ -96,6 +111,7 @@ int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap) ret = __tb_port_find_cap(port, cap); + tb_port_dummy_read(port); tb_port_enable_tmu(port, false); return ret; -- 2.20.1