From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753174Ab2G2C4D (ORCPT ); Sat, 28 Jul 2012 22:56:03 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:57953 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753165Ab2G2C4A (ORCPT ); Sat, 28 Jul 2012 22:56:00 -0400 Message-ID: <1343530554.5373.3.camel@phoenix> Subject: [PATCH RFT 2/2] gpio: gpio-pch: Use spinlock for register access protection From: Axel Lin To: linux-kernel@vger.kernel.org Cc: Feng Tang , Tomoya MORINAGA , Grant Likely , Linus Walleij Date: Sun, 29 Jul 2012 10:55:54 +0800 In-Reply-To: <1343530482.5373.2.camel@phoenix> References: <1343530482.5373.2.camel@phoenix> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org gpio_chip.can_sleep is 0, but current code uses mutex in pch_gpio_set pch_gpio_get and pch_gpio_direction_input functions. Thus those functions are not callable from interrupt context. This patch converts mutex into spinlock. Signed-off-by: Axel Lin --- drivers/gpio/gpio-pch.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/drivers/gpio/gpio-pch.c b/drivers/gpio/gpio-pch.c index 139ad3e..4ad0c4f 100644 --- a/drivers/gpio/gpio-pch.c +++ b/drivers/gpio/gpio-pch.c @@ -92,9 +92,7 @@ struct pch_gpio_reg_data { * @lock: Used for register access protection * @irq_base: Save base of IRQ number for interrupt * @ioh: IOH ID - * @spinlock: Used for register access protection in - * interrupt context pch_irq_mask, - * pch_irq_unmask and pch_irq_type; + * @spinlock: Used for register access protection */ struct pch_gpio { void __iomem *base; @@ -102,7 +100,6 @@ struct pch_gpio { struct device *dev; struct gpio_chip gpio; struct pch_gpio_reg_data pch_gpio_reg; - struct mutex lock; int irq_base; enum pch_type_t ioh; spinlock_t spinlock; @@ -112,8 +109,9 @@ static void pch_gpio_set(struct gpio_chip *gpio, unsigned nr, int val) { u32 reg_val; struct pch_gpio *chip = container_of(gpio, struct pch_gpio, gpio); + unsigned long flags; - mutex_lock(&chip->lock); + spin_lock_irqsave(&chip->spinlock, flags); reg_val = ioread32(&chip->reg->po); if (val) reg_val |= (1 << nr); @@ -121,7 +119,7 @@ static void pch_gpio_set(struct gpio_chip *gpio, unsigned nr, int val) reg_val &= ~(1 << nr); iowrite32(reg_val, &chip->reg->po); - mutex_unlock(&chip->lock); + spin_unlock_irqrestore(&chip->spinlock, flags); } static int pch_gpio_get(struct gpio_chip *gpio, unsigned nr) @@ -137,8 +135,9 @@ static int pch_gpio_direction_output(struct gpio_chip *gpio, unsigned nr, struct pch_gpio *chip = container_of(gpio, struct pch_gpio, gpio); u32 pm; u32 reg_val; + unsigned long flags; - mutex_lock(&chip->lock); + spin_lock_irqsave(&chip->spinlock, flags); pm = ioread32(&chip->reg->pm) & ((1 << gpio_pins[chip->ioh]) - 1); pm |= (1 << nr); iowrite32(pm, &chip->reg->pm); @@ -149,8 +148,7 @@ static int pch_gpio_direction_output(struct gpio_chip *gpio, unsigned nr, else reg_val &= ~(1 << nr); iowrite32(reg_val, &chip->reg->po); - - mutex_unlock(&chip->lock); + spin_unlock_irqrestore(&chip->spinlock, flags); return 0; } @@ -159,12 +157,13 @@ static int pch_gpio_direction_input(struct gpio_chip *gpio, unsigned nr) { struct pch_gpio *chip = container_of(gpio, struct pch_gpio, gpio); u32 pm; + unsigned long flags; - mutex_lock(&chip->lock); + spin_lock_irqsave(&chip->spinlock, flags); pm = ioread32(&chip->reg->pm) & ((1 << gpio_pins[chip->ioh]) - 1); pm &= ~(1 << nr); iowrite32(pm, &chip->reg->pm); - mutex_unlock(&chip->lock); + spin_unlock_irqrestore(&chip->spinlock, flags); return 0; } @@ -387,7 +386,6 @@ static int __devinit pch_gpio_probe(struct pci_dev *pdev, chip->reg = chip->base; pci_set_drvdata(pdev, chip); - mutex_init(&chip->lock); spin_lock_init(&chip->spinlock); pch_gpio_setup(chip); ret = gpiochip_add(&chip->gpio); -- 1.7.9.5