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=-3.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 4A871C65BAF for ; Sun, 9 Dec 2018 22:03:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1809320661 for ; Sun, 9 Dec 2018 22:03:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1809320661 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726614AbeLIVz2 (ORCPT ); Sun, 9 Dec 2018 16:55:28 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34696 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726390AbeLIVzM (ORCPT ); Sun, 9 Dec 2018 16:55:12 -0500 Received: from pub.yeoldevic.com ([81.174.156.145] helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gW72b-0002iq-M4; Sun, 09 Dec 2018 21:55:09 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gW72Z-0003Ef-2m; Sun, 09 Dec 2018 21:55:07 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Thierry Reding" , "Jon Hunter" Date: Sun, 09 Dec 2018 21:50:33 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 032/328] ARM: tegra: Fix Tegra30 Cardhu PCA954x reset In-Reply-To: X-SA-Exim-Connect-IP: 81.174.156.145 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.62-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jon Hunter commit 6e1811900b6fe6f2b4665dba6bd6ed32c6b98575 upstream. On all versions of Tegra30 Cardhu, the reset signal to the NXP PCA9546 I2C mux is connected to the Tegra GPIO BB0. Currently, this pin on the Tegra is not configured as a GPIO but as a special-function IO (SFIO) that is multiplexing the pin to an I2S controller. On exiting system suspend, I2C commands sent to the PCA9546 are failing because there is no ACK. Although it is not possible to see exactly what is happening to the reset during suspend, by ensuring it is configured as a GPIO and driven high, to de-assert the reset, the failures are no longer seen. Please note that this GPIO is also used to drive the reset signal going to the camera connector on the board. However, given that there is no camera support currently for Cardhu, this should not have any impact. Fixes: 40431d16ff11 ("ARM: tegra: enable PCA9546 on Cardhu") Signed-off-by: Jon Hunter Signed-off-by: Thierry Reding Signed-off-by: Ben Hutchings --- arch/arm/boot/dts/tegra30-cardhu.dtsi | 1 + 1 file changed, 1 insertion(+) --- a/arch/arm/boot/dts/tegra30-cardhu.dtsi +++ b/arch/arm/boot/dts/tegra30-cardhu.dtsi @@ -193,6 +193,7 @@ #address-cells = <1>; #size-cells = <0>; reg = <0x70>; + reset-gpio = <&gpio TEGRA_GPIO(BB, 0) GPIO_ACTIVE_LOW>; }; };