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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,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 1BFE0C2B9FF for ; Wed, 12 May 2021 16:30:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F250761263 for ; Wed, 12 May 2021 16:30:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240708AbhELQam (ORCPT ); Wed, 12 May 2021 12:30:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:56688 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234318AbhELPjZ (ORCPT ); Wed, 12 May 2021 11:39:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D9F4F61C73; Wed, 12 May 2021 15:20:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620832849; bh=9UeP8We+m4Gx6md/+WvfJYb09b3nl5dZm2zWAqiBTBk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HUaHF9RTpXWEt7YDe6ygbSPCiT3UMlUguMWs5SXnK+6rndg4+AGUSI7XmSluvoFVy dIP0gF/sxwiMQC8IsRNLTaslvMOoqgbTmBfHwN6K82Uvy4ug3IZ3oUPgj+3dQogTkT PC8VWaPZ2gywJ/+G0PQEoWp613h7++3nPg3gNzNU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wolfram Sang , =?UTF-8?q?Niklas=20S=C3=B6derlund?= , Wolfram Sang , Sasha Levin Subject: [PATCH 5.10 441/530] i2c: rcar: protect against supurious interrupts on V3U Date: Wed, 12 May 2021 16:49:11 +0200 Message-Id: <20210512144834.270178251@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144819.664462530@linuxfoundation.org> References: <20210512144819.664462530@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wolfram Sang [ Upstream commit 9c975c432bc0aa53a90438fc80b369cb35134a48 ] V3U creates spurious interrupts which we need to handle. This costs time until BUS_PHASE_DATA can be activated which is problematic for Gen2 SoCs and earlier. Because of this we introduce two interrupt handlers here which will call a generic main irq function once the timing critical stuff is done. Signed-off-by: Wolfram Sang Reviewed-by: Niklas Söderlund Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-rcar.c | 57 ++++++++++++++++++++++++++--------- 1 file changed, 43 insertions(+), 14 deletions(-) diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 3c9c3a6f7ac8..12f6d452c0f7 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -625,20 +625,11 @@ static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv) * generated. It turned out that taking a spinlock at the beginning of the ISR * was already causing repeated messages. Thus, this driver was converted to * the now lockless behaviour. Please keep this in mind when hacking the driver. + * R-Car Gen3 seems to have this fixed but earlier versions than R-Car Gen2 are + * likely affected. Therefore, we have different interrupt handler entries. */ -static irqreturn_t rcar_i2c_irq(int irq, void *ptr) +static irqreturn_t rcar_i2c_irq(int irq, struct rcar_i2c_priv *priv, u32 msr) { - struct rcar_i2c_priv *priv = ptr; - u32 msr; - - /* Clear START or STOP immediately, except for REPSTART after read */ - if (likely(!(priv->flags & ID_P_REP_AFTER_RD))) - rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA); - - msr = rcar_i2c_read(priv, ICMSR); - - /* Only handle interrupts that are currently enabled */ - msr &= rcar_i2c_read(priv, ICMIER); if (!msr) { if (rcar_i2c_slave_irq(priv)) return IRQ_HANDLED; @@ -682,6 +673,41 @@ out: return IRQ_HANDLED; } +static irqreturn_t rcar_i2c_gen2_irq(int irq, void *ptr) +{ + struct rcar_i2c_priv *priv = ptr; + u32 msr; + + /* Clear START or STOP immediately, except for REPSTART after read */ + if (likely(!(priv->flags & ID_P_REP_AFTER_RD))) + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA); + + /* Only handle interrupts that are currently enabled */ + msr = rcar_i2c_read(priv, ICMSR); + msr &= rcar_i2c_read(priv, ICMIER); + + return rcar_i2c_irq(irq, priv, msr); +} + +static irqreturn_t rcar_i2c_gen3_irq(int irq, void *ptr) +{ + struct rcar_i2c_priv *priv = ptr; + u32 msr; + + /* Only handle interrupts that are currently enabled */ + msr = rcar_i2c_read(priv, ICMSR); + msr &= rcar_i2c_read(priv, ICMIER); + + /* + * Clear START or STOP immediately, except for REPSTART after read or + * if a spurious interrupt was detected. + */ + if (likely(!(priv->flags & ID_P_REP_AFTER_RD) && msr)) + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA); + + return rcar_i2c_irq(irq, priv, msr); +} + static struct dma_chan *rcar_i2c_request_dma_chan(struct device *dev, enum dma_transfer_direction dir, dma_addr_t port_addr) @@ -929,6 +955,7 @@ static int rcar_i2c_probe(struct platform_device *pdev) struct i2c_adapter *adap; struct device *dev = &pdev->dev; unsigned long irqflags = 0; + irqreturn_t (*irqhandler)(int irq, void *ptr) = rcar_i2c_gen3_irq; int ret; /* Otherwise logic will break because some bytes must always use PIO */ @@ -977,8 +1004,10 @@ static int rcar_i2c_probe(struct platform_device *pdev) rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */ - if (priv->devtype < I2C_RCAR_GEN3) + if (priv->devtype < I2C_RCAR_GEN3) { irqflags |= IRQF_NO_THREAD; + irqhandler = rcar_i2c_gen2_irq; + } if (priv->devtype == I2C_RCAR_GEN3) { priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); @@ -999,7 +1028,7 @@ static int rcar_i2c_probe(struct platform_device *pdev) priv->flags |= ID_P_HOST_NOTIFY; priv->irq = platform_get_irq(pdev, 0); - ret = devm_request_irq(dev, priv->irq, rcar_i2c_irq, irqflags, dev_name(dev), priv); + ret = devm_request_irq(dev, priv->irq, irqhandler, irqflags, dev_name(dev), priv); if (ret < 0) { dev_err(dev, "cannot get irq %d\n", priv->irq); goto out_pm_disable; -- 2.30.2