From patchwork Mon May 4 17:57:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 226369 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=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 72237C4724C for ; Mon, 4 May 2020 18:11:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 49D7720663 for ; Mon, 4 May 2020 18:11:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588615875; bh=YkAKodN6UufF5X2rzXlFeZr6xUI5WiB5/Lb6gaqDR/c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=v4UErKivdWYtrdTx0JF0IeKawvZIL93WNBsITO78jrlaJ941R6yXDxWFfkSx9z1M6 cwgRW9OVwjZei5rFyDcRFnfP6rmbQjklzTbsZfNSyubOPCrTBUD8Q/5dhN7ZUXRd0R TMkuw8k/F7jtz553EEfqMwYEjNZQ4OOscOhoTA4g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731660AbgEDSEZ (ORCPT ); Mon, 4 May 2020 14:04:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:33782 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731670AbgEDSEY (ORCPT ); Mon, 4 May 2020 14:04:24 -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 BE680205ED; Mon, 4 May 2020 18:04:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588615464; bh=YkAKodN6UufF5X2rzXlFeZr6xUI5WiB5/Lb6gaqDR/c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ERJFvegprR+5K+vwLN71VhJ3lL0MFNSEYI5DGpu/pIRIkDStmEE0Zr+nzrzSjT5hP 4sk6fLdGYtIYeghBES3jTCaK9XtrcoaDDp5ReZwDsWUBH5ch79VuEC0v7GvnYeK7gV 0BB0Xx6vB3rn8hw2vuTTDjdjDsLIY8eB7tGXuSjg= 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 5.4 49/57] i2c: aspeed: Avoid i2c interrupt status clear race condition. Date: Mon, 4 May 2020 19:57:53 +0200 Message-Id: <20200504165500.835261420@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200504165456.783676004@linuxfoundation.org> References: <20200504165456.783676004@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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; }