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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 0622BC00454 for ; Mon, 9 Dec 2019 13:09:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8D0B2073D for ; Mon, 9 Dec 2019 13:09:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727038AbfLINJa (ORCPT ); Mon, 9 Dec 2019 08:09:30 -0500 Received: from mga09.intel.com ([134.134.136.24]:48019 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727312AbfLINJa (ORCPT ); Mon, 9 Dec 2019 08:09:30 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Dec 2019 05:09:29 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,294,1571727600"; d="scan'208";a="362921928" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga004.jf.intel.com with ESMTP; 09 Dec 2019 05:09:28 -0800 Received: by black.fi.intel.com (Postfix, from userid 1003) id 43A77269; Mon, 9 Dec 2019 15:09:27 +0200 (EET) From: Andy Shevchenko To: Linus Walleij , Bartosz Golaszewski , linux-gpio@vger.kernel.org, Mika Westerberg Cc: Andy Shevchenko Subject: [PATCH v2 02/24] pinctrl: lynxpoint: Use raw_spinlock for locking Date: Mon, 9 Dec 2019 15:09:04 +0200 Message-Id: <20191209130926.86483-3-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191209130926.86483-1-andriy.shevchenko@linux.intel.com> References: <20191209130926.86483-1-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org The Intel Lynxpoint pinctrl driver implements irqchip callbacks which are called with desc->lock raw_spinlock held. In mainline this is fine because spinlock resolves to raw_spinlock. However, running the same code in -rt we will get a BUG() asserted. This is because in -rt spinlocks are preemptible so taking the driver private spinlock in irqchip callbacks causes might_sleep() to trigger. In order to keep -rt happy but at the same time make sure that register accesses get serialized, convert the driver to use raw_spinlock instead. Signed-off-by: Andy Shevchenko --- drivers/pinctrl/intel/pinctrl-lynxpoint.c | 28 +++++++++++------------ 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/drivers/pinctrl/intel/pinctrl-lynxpoint.c b/drivers/pinctrl/intel/pinctrl-lynxpoint.c index 490ce7bae25e..c30fd86846a7 100644 --- a/drivers/pinctrl/intel/pinctrl-lynxpoint.c +++ b/drivers/pinctrl/intel/pinctrl-lynxpoint.c @@ -47,7 +47,7 @@ struct lp_gpio { struct gpio_chip chip; struct platform_device *pdev; - spinlock_t lock; + raw_spinlock_t lock; unsigned long reg_base; }; @@ -144,7 +144,7 @@ static int lp_irq_type(struct irq_data *d, unsigned type) if (hwirq >= lg->chip.ngpio) return -EINVAL; - spin_lock_irqsave(&lg->lock, flags); + raw_spin_lock_irqsave(&lg->lock, flags); value = inl(reg); /* set both TRIG_SEL and INV bits to 0 for rising edge */ @@ -170,7 +170,7 @@ static int lp_irq_type(struct irq_data *d, unsigned type) else if (type & IRQ_TYPE_LEVEL_MASK) irq_set_handler_locked(d, handle_level_irq); - spin_unlock_irqrestore(&lg->lock, flags); + raw_spin_unlock_irqrestore(&lg->lock, flags); return 0; } @@ -187,14 +187,14 @@ static void lp_gpio_set(struct gpio_chip *chip, unsigned offset, int value) unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1); unsigned long flags; - spin_lock_irqsave(&lg->lock, flags); + raw_spin_lock_irqsave(&lg->lock, flags); if (value) outl(inl(reg) | OUT_LVL_BIT, reg); else outl(inl(reg) & ~OUT_LVL_BIT, reg); - spin_unlock_irqrestore(&lg->lock, flags); + raw_spin_unlock_irqrestore(&lg->lock, flags); } static int lp_gpio_direction_input(struct gpio_chip *chip, unsigned offset) @@ -203,9 +203,9 @@ static int lp_gpio_direction_input(struct gpio_chip *chip, unsigned offset) unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1); unsigned long flags; - spin_lock_irqsave(&lg->lock, flags); + raw_spin_lock_irqsave(&lg->lock, flags); outl(inl(reg) | DIR_BIT, reg); - spin_unlock_irqrestore(&lg->lock, flags); + raw_spin_unlock_irqrestore(&lg->lock, flags); return 0; } @@ -219,9 +219,9 @@ static int lp_gpio_direction_output(struct gpio_chip *chip, lp_gpio_set(chip, offset, value); - spin_lock_irqsave(&lg->lock, flags); + raw_spin_lock_irqsave(&lg->lock, flags); outl(inl(reg) & ~DIR_BIT, reg); - spin_unlock_irqrestore(&lg->lock, flags); + raw_spin_unlock_irqrestore(&lg->lock, flags); return 0; } @@ -272,9 +272,9 @@ static void lp_irq_enable(struct irq_data *d) unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_ENABLE); unsigned long flags; - spin_lock_irqsave(&lg->lock, flags); + raw_spin_lock_irqsave(&lg->lock, flags); outl(inl(reg) | BIT(hwirq % 32), reg); - spin_unlock_irqrestore(&lg->lock, flags); + raw_spin_unlock_irqrestore(&lg->lock, flags); } static void lp_irq_disable(struct irq_data *d) @@ -285,9 +285,9 @@ static void lp_irq_disable(struct irq_data *d) unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_ENABLE); unsigned long flags; - spin_lock_irqsave(&lg->lock, flags); + raw_spin_lock_irqsave(&lg->lock, flags); outl(inl(reg) & ~BIT(hwirq % 32), reg); - spin_unlock_irqrestore(&lg->lock, flags); + raw_spin_unlock_irqrestore(&lg->lock, flags); } static struct irq_chip lp_irqchip = { @@ -351,7 +351,7 @@ static int lp_gpio_probe(struct platform_device *pdev) return -EBUSY; } - spin_lock_init(&lg->lock); + raw_spin_lock_init(&lg->lock); gc = &lg->chip; gc->label = dev_name(dev); -- 2.24.0