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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 AAA22C3A5A9 for ; Mon, 4 May 2020 18:07:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F9F7205ED for ; Mon, 4 May 2020 18:07:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588615645; bh=YkAKodN6UufF5X2rzXlFeZr6xUI5WiB5/Lb6gaqDR/c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=V4C89xmQLqRg6mwl/7WIsBINmgTxtYEzRdMhJTcoAanTvm4WHsVE54Qi5/f43r4to 5MYhABgQeJjyeTBZsuG9FJ1Mpzk1UK3ackVGdr/rPoMlRbU77uCeo2qLX55KsHp8YB WQgVXdQPLvF605AvA7SXX1hHorHCPUWd4I1QkgRo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732139AbgEDSHY (ORCPT ); Mon, 4 May 2020 14:07:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:38086 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732104AbgEDSHU (ORCPT ); Mon, 4 May 2020 14:07:20 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3308C205ED; Mon, 4 May 2020 18:07:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588615639; bh=YkAKodN6UufF5X2rzXlFeZr6xUI5WiB5/Lb6gaqDR/c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NREXNb1hL6BBTHFxcB3/MbCElCIA8P7NLFAwU8DPP/2TBwFMlqydab4hdeUgsoyo6 JWt6gUToNLRuYVOL2p9f/aT/wIxzbC69DK/xEDdOyYCVFbusjCeqr7j4wJ26v72Vet WT3uPBC7yn0Gp0W4Kglfq1W4YmGwSZMlNde3WUDo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, ryan_chen , Benjamin Herrenschmidt , Wolfram Sang Subject: [PATCH 5.6 63/73] i2c: aspeed: Avoid i2c interrupt status clear race condition. Date: Mon, 4 May 2020 19:58:06 +0200 Message-Id: <20200504165509.990369803@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200504165501.781878940@linuxfoundation.org> References: <20200504165501.781878940@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: ryan_chen commit c926c87b8e36dcc0ea5c2a0a0227ed4f32d0516a upstream. In AST2600 there have a slow peripheral bus between CPU and i2c controller. Therefore GIC i2c interrupt status clear have delay timing, when CPU issue write clear i2c controller interrupt status. To avoid this issue, the driver need have read after write clear at i2c ISR. Fixes: f327c686d3ba ("i2c: aspeed: added driver for Aspeed I2C") Signed-off-by: ryan_chen Acked-by: Benjamin Herrenschmidt [wsa: added Fixes tag] Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-aspeed.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/i2c/busses/i2c-aspeed.c +++ b/drivers/i2c/busses/i2c-aspeed.c @@ -603,6 +603,7 @@ static irqreturn_t aspeed_i2c_bus_irq(in /* Ack all interrupts except for Rx done */ writel(irq_received & ~ASPEED_I2CD_INTR_RX_DONE, bus->base + ASPEED_I2C_INTR_STS_REG); + readl(bus->base + ASPEED_I2C_INTR_STS_REG); irq_remaining = irq_received; #if IS_ENABLED(CONFIG_I2C_SLAVE) @@ -645,9 +646,11 @@ static irqreturn_t aspeed_i2c_bus_irq(in irq_received, irq_handled); /* Ack Rx done */ - if (irq_received & ASPEED_I2CD_INTR_RX_DONE) + if (irq_received & ASPEED_I2CD_INTR_RX_DONE) { writel(ASPEED_I2CD_INTR_RX_DONE, bus->base + ASPEED_I2C_INTR_STS_REG); + readl(bus->base + ASPEED_I2C_INTR_STS_REG); + } spin_unlock(&bus->lock); return irq_remaining ? IRQ_NONE : IRQ_HANDLED; }