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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=unavailable 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 06A4FC43218 for ; Sat, 27 Apr 2019 15:29:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C6CC6208C2 for ; Sat, 27 Apr 2019 15:29:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728424AbfD0P3T (ORCPT ); Sat, 27 Apr 2019 11:29:19 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:32980 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727306AbfD0PPT (ORCPT ); Sat, 27 Apr 2019 11:15:19 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hKP2q-0000zP-2J; Sat, 27 Apr 2019 16:15:16 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hKP2m-0004c4-Ps; Sat, 27 Apr 2019 16:15:12 +0100 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, Denis Kirjanov , "Michal Simek" , "Wolfram Sang" , "Kyle Roeschley" , "Shubhrajyoti Datta" Date: Sat, 27 Apr 2019 16:13:09 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 160/202] i2c: cadence: Fix the hold bit setting In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 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 3.16.66-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Shubhrajyoti Datta commit d358def706880defa4c9e87381c5bf086a97d5f9 upstream. In case the hold bit is not needed we are carrying the old values. Fix the same by resetting the bit when not needed. Fixes the sporadic i2c bus lockups on National Instruments Zynq-based devices. Fixes: df8eb5691c48 ("i2c: Add driver for Cadence I2C controller") Reported-by: Kyle Roeschley Acked-by: Michal Simek Signed-off-by: Shubhrajyoti Datta Tested-by: Kyle Roeschley Signed-off-by: Wolfram Sang Signed-off-by: Ben Hutchings --- drivers/i2c/busses/i2c-cadence.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/drivers/i2c/busses/i2c-cadence.c +++ b/drivers/i2c/busses/i2c-cadence.c @@ -320,8 +320,10 @@ static void cdns_i2c_mrecv(struct cdns_i * Check for the message size against FIFO depth and set the * 'hold bus' bit if it is greater than FIFO depth. */ - if (id->recv_count > CDNS_I2C_FIFO_DEPTH) + if ((id->recv_count > CDNS_I2C_FIFO_DEPTH) || id->bus_hold_flag) ctrl_reg |= CDNS_I2C_CR_HOLD; + else + ctrl_reg = ctrl_reg & ~CDNS_I2C_CR_HOLD; cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET); @@ -375,8 +377,11 @@ static void cdns_i2c_msend(struct cdns_i * Check for the message size against FIFO depth and set the * 'hold bus' bit if it is greater than FIFO depth. */ - if (id->send_count > CDNS_I2C_FIFO_DEPTH) + if ((id->send_count > CDNS_I2C_FIFO_DEPTH) || id->bus_hold_flag) ctrl_reg |= CDNS_I2C_CR_HOLD; + else + ctrl_reg = ctrl_reg & ~CDNS_I2C_CR_HOLD; + cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET); /* Clear the interrupts in interrupt status register. */