From patchwork Thu Jun 27 15:00:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Piotr Wojtaszczyk X-Patchwork-Id: 1953391 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=timesys-com.20230601.gappssmtp.com header.i=@timesys-com.20230601.gappssmtp.com header.a=rsa-sha256 header.s=20230601 header.b=V0FETp6o; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=patchwork.ozlabs.org) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4W926q5ST9z20XB for ; Fri, 28 Jun 2024 01:09:55 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=timesys-com.20230601.gappssmtp.com header.i=@timesys-com.20230601.gappssmtp.com header.a=rsa-sha256 header.s=20230601 header.b=V0FETp6o; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4W926p0RYGz3fpl for ; Fri, 28 Jun 2024 01:09:54 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=timesys.com Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=timesys-com.20230601.gappssmtp.com header.i=@timesys-com.20230601.gappssmtp.com header.a=rsa-sha256 header.s=20230601 header.b=V0FETp6o; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=timesys.com (client-ip=2a00:1450:4864:20::62c; helo=mail-ej1-x62c.google.com; envelope-from=piotr.wojtaszczyk@timesys.com; receiver=lists.ozlabs.org) Received: from mail-ej1-x62c.google.com (mail-ej1-x62c.google.com [IPv6:2a00:1450:4864:20::62c]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4W921b118Bz3d2N for ; Fri, 28 Jun 2024 01:05:22 +1000 (AEST) Received: by mail-ej1-x62c.google.com with SMTP id a640c23a62f3a-a728f74c23dso254382666b.1 for ; Thu, 27 Jun 2024 08:05:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=timesys-com.20230601.gappssmtp.com; s=20230601; t=1719500720; x=1720105520; darn=lists.ozlabs.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:from:to:cc:subject:date:message-id :reply-to; bh=c0en4a04xGUdMe3CHuzskBvRxKjfQMua42qeg+gKOfI=; b=V0FETp6ojE28pMaGSlXun1BCgwI1TyOUcC3BMKACCSlICgCb30/hVwdAk+rQg6orpW YgfjbLuHXA2rh6Q9GE+WI3O27Ti2tjiKm/WRPN8JaZhK0enwfxOkoMJlzPemy9gocAgB dQahZuF36z8VsX+zkhoxH6naCUkaiBlR0siB/GWXRAIAzuHqxdnrm850h6jhwxhwzvtt /jYBNHFrzJ3nRRGZU3M+9JgXfIHJ/8fb0T/3Y9HV70gifbgR4q9TIB2DKKdgcHfSGLF3 jWjj2aVxL34rfE/WK9rHqmEBIifdRItSfHlaVXJ/1GUCRSqdr4YIsgX/AtRQNFZJ6l3b EqxA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1719500720; x=1720105520; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=c0en4a04xGUdMe3CHuzskBvRxKjfQMua42qeg+gKOfI=; b=ujhzx2aixCOLWJMZUBH493BAtMS+Sk5HXzRh8VP8TbpImMoEFXsclx+92ZB2fbADxl 9hSzUjzdy+hTCtCVGH6Ldrsx2G98jKHiyHUUyiOAvmepJb9p6gktxVgiDybgXCn3Iw7A QVyhzpA+I5a4L7JTohagEofjNrKBEXe1GDrNtSbI/KUdkwYl2VykkzidbkDnk2fszGfh 3U278HiP+n/OtMZfuo63kDAlxDqXXU+dR3sYBNrCS7bsnbR7eGzJCLsMop2vvkOJZcSI uomiZH816plCn1scKa6tuxLNmsB0g3ohBj662nRsSBAVpCCT53TSwwRfHjORBUZhJixe h1uA== X-Forwarded-Encrypted: i=1; AJvYcCVJsaYrS9/yee7pTRduCU+1aOBQw/dTwFERYog+elWznTk6rfgJzkFBgO0X2lmKrWngP0tu4wNv3vu+A47xcun2HUJAaOvZG+ZUhf0H+g== X-Gm-Message-State: AOJu0YxB8RBPVlbqF8qf2mHyh2VH95FWk2NBrjUXu7HBsSIHZfCCmP+9 CpkpoevV+CWzltwVgTe3taO3i1ieBFxzBZOCWM27KBEWaYUqWAobcidPXota55U= X-Google-Smtp-Source: AGHT+IFWt98+h6PiAC5RUj8DxZquK6YDjOivxXx0avHukTQoTFEMXOT45G3SobQ5Q+1zYPM7YJ42Nw== X-Received: by 2002:a17:907:3ad4:b0:a6f:4de6:79f with SMTP id a640c23a62f3a-a7245bad98emr764943466b.40.1719500720489; Thu, 27 Jun 2024 08:05:20 -0700 (PDT) Received: from localhost.localdomain ([91.216.213.152]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a729d7ca289sm67189066b.222.2024.06.27.08.05.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 27 Jun 2024 08:05:19 -0700 (PDT) From: Piotr Wojtaszczyk To: Vinod Koul , Rob Herring , Krzysztof Kozlowski , Conor Dooley , "J.M.B. Downing" , Piotr Wojtaszczyk , Vladimir Zapolskiy , Liam Girdwood , Mark Brown , Russell King , Michael Turquette , Stephen Boyd , Andi Shyti , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Jaroslav Kysela , Takashi Iwai , Yangtao Li , Arnd Bergmann , Li Zetao , Chancel Liu , Michael Ellerman , Corentin Labbe , dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, alsa-devel@alsa-project.org, linuxppc-dev@lists.ozlabs.org, linux-sound@vger.kernel.org, linux-clk@vger.kernel.org, linux-i2c@vger.kernel.org, linux-mtd@lists.infradead.org Subject: [Patch v5 12/12] i2x: pnx: Fix potential deadlock warning from del_timer_sync() call in isr Date: Thu, 27 Jun 2024 17:00:30 +0200 Message-Id: <20240627150046.258795-13-piotr.wojtaszczyk@timesys.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240627150046.258795-1-piotr.wojtaszczyk@timesys.com> References: <20240627150046.258795-1-piotr.wojtaszczyk@timesys.com> MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" When del_timer_sync() is called in an interrupt context it throws a warning because of potential deadlock. The timer is used only to exit from wait_for_completion() after a timeout so replacing the call with wait_for_completion_timeout() allows to remove the problematic timer and its related functions altogether. Signed-off-by: Piotr Wojtaszczyk --- Changes for v5: - Replaced wait_for_completion() with wait_for_completion_timeout(). - Removed unneded "alg_data->mif.timer" and its functions - Request irq with devm_request_irq() as before the patch - Renamed the patch and reword description for the new way to fix the warning Changes for v4: - Request irq with devm_request_threaded_irq() to prevent the warning drivers/i2c/busses/i2c-pnx.c | 48 ++++++++---------------------------- 1 file changed, 10 insertions(+), 38 deletions(-) diff --git a/drivers/i2c/busses/i2c-pnx.c b/drivers/i2c/busses/i2c-pnx.c index a12525b3186b..f448505d5468 100644 --- a/drivers/i2c/busses/i2c-pnx.c +++ b/drivers/i2c/busses/i2c-pnx.c @@ -15,7 +15,6 @@ #include #include #include -#include #include #include #include @@ -32,7 +31,6 @@ struct i2c_pnx_mif { int ret; /* Return value */ int mode; /* Interface mode */ struct completion complete; /* I/O completion */ - struct timer_list timer; /* Timeout */ u8 * buf; /* Data buffer */ int len; /* Length of data buffer */ int order; /* RX Bytes to order via TX */ @@ -117,24 +115,6 @@ static inline int wait_reset(struct i2c_pnx_algo_data *data) return (timeout <= 0); } -static inline void i2c_pnx_arm_timer(struct i2c_pnx_algo_data *alg_data) -{ - struct timer_list *timer = &alg_data->mif.timer; - unsigned long expires = msecs_to_jiffies(alg_data->timeout); - - if (expires <= 1) - expires = 2; - - del_timer_sync(timer); - - dev_dbg(&alg_data->adapter.dev, "Timer armed at %lu plus %lu jiffies.\n", - jiffies, expires); - - timer->expires = jiffies + expires; - - add_timer(timer); -} - /** * i2c_pnx_start - start a device * @slave_addr: slave address @@ -259,8 +239,6 @@ static int i2c_pnx_master_xmit(struct i2c_pnx_algo_data *alg_data) ~(mcntrl_afie | mcntrl_naie | mcntrl_drmie), I2C_REG_CTL(alg_data)); - del_timer_sync(&alg_data->mif.timer); - dev_dbg(&alg_data->adapter.dev, "%s(): Waking up xfer routine.\n", __func__); @@ -276,8 +254,6 @@ static int i2c_pnx_master_xmit(struct i2c_pnx_algo_data *alg_data) ~(mcntrl_afie | mcntrl_naie | mcntrl_drmie), I2C_REG_CTL(alg_data)); - /* Stop timer. */ - del_timer_sync(&alg_data->mif.timer); dev_dbg(&alg_data->adapter.dev, "%s(): Waking up xfer routine after zero-xfer.\n", __func__); @@ -364,8 +340,6 @@ static int i2c_pnx_master_rcv(struct i2c_pnx_algo_data *alg_data) mcntrl_drmie | mcntrl_daie); iowrite32(ctl, I2C_REG_CTL(alg_data)); - /* Kill timer. */ - del_timer_sync(&alg_data->mif.timer); complete(&alg_data->mif.complete); } } @@ -400,8 +374,6 @@ static irqreturn_t i2c_pnx_interrupt(int irq, void *dev_id) mcntrl_drmie); iowrite32(ctl, I2C_REG_CTL(alg_data)); - /* Stop timer, to prevent timeout. */ - del_timer_sync(&alg_data->mif.timer); complete(&alg_data->mif.complete); } else if (stat & mstatus_nai) { /* Slave did not acknowledge, generate a STOP */ @@ -419,8 +391,6 @@ static irqreturn_t i2c_pnx_interrupt(int irq, void *dev_id) /* Our return value. */ alg_data->mif.ret = -EIO; - /* Stop timer, to prevent timeout. */ - del_timer_sync(&alg_data->mif.timer); complete(&alg_data->mif.complete); } else { /* @@ -453,9 +423,8 @@ static irqreturn_t i2c_pnx_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } -static void i2c_pnx_timeout(struct timer_list *t) +static void i2c_pnx_timeout(struct i2c_pnx_algo_data *alg_data) { - struct i2c_pnx_algo_data *alg_data = from_timer(alg_data, t, mif.timer); u32 ctl; dev_err(&alg_data->adapter.dev, @@ -472,7 +441,6 @@ static void i2c_pnx_timeout(struct timer_list *t) iowrite32(ctl, I2C_REG_CTL(alg_data)); wait_reset(alg_data); alg_data->mif.ret = -EIO; - complete(&alg_data->mif.complete); } static inline void bus_reset_if_active(struct i2c_pnx_algo_data *alg_data) @@ -514,6 +482,7 @@ i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) struct i2c_msg *pmsg; int rc = 0, completed = 0, i; struct i2c_pnx_algo_data *alg_data = adap->algo_data; + unsigned long time_left; u32 stat; dev_dbg(&alg_data->adapter.dev, @@ -548,7 +517,6 @@ i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) dev_dbg(&alg_data->adapter.dev, "%s(): mode %d, %d bytes\n", __func__, alg_data->mif.mode, alg_data->mif.len); - i2c_pnx_arm_timer(alg_data); /* initialize the completion var */ init_completion(&alg_data->mif.complete); @@ -564,7 +532,10 @@ i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) break; /* Wait for completion */ - wait_for_completion(&alg_data->mif.complete); + time_left = wait_for_completion_timeout(&alg_data->mif.complete, + alg_data->timeout); + if (time_left == 0) + i2c_pnx_timeout(alg_data); if (!(rc = alg_data->mif.ret)) completed++; @@ -653,7 +624,10 @@ static int i2c_pnx_probe(struct platform_device *pdev) alg_data->adapter.algo_data = alg_data; alg_data->adapter.nr = pdev->id; - alg_data->timeout = I2C_PNX_TIMEOUT_DEFAULT; + alg_data->timeout = msecs_to_jiffies(I2C_PNX_TIMEOUT_DEFAULT); + if (alg_data->timeout <= 1) + alg_data->timeout = 2; + #ifdef CONFIG_OF alg_data->adapter.dev.of_node = of_node_get(pdev->dev.of_node); if (pdev->dev.of_node) { @@ -673,8 +647,6 @@ static int i2c_pnx_probe(struct platform_device *pdev) if (IS_ERR(alg_data->clk)) return PTR_ERR(alg_data->clk); - timer_setup(&alg_data->mif.timer, i2c_pnx_timeout, 0); - snprintf(alg_data->adapter.name, sizeof(alg_data->adapter.name), "%s", pdev->name);