From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753091Ab2G2Cyw (ORCPT ); Sat, 28 Jul 2012 22:54:52 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:36604 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752741Ab2G2Cyv (ORCPT ); Sat, 28 Jul 2012 22:54:51 -0400 Message-ID: <1343530482.5373.2.camel@phoenix> Subject: [PATCH RFT 1/2] gpio: gpio-ml-ioh: 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 10:54:42 +0800 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 ioh_gpio_set, ioh_gpio_get and ioh_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-ml-ioh.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/drivers/gpio/gpio-ml-ioh.c b/drivers/gpio/gpio-ml-ioh.c index db01f15..6a29ee1 100644 --- a/drivers/gpio/gpio-ml-ioh.c +++ b/drivers/gpio/gpio-ml-ioh.c @@ -87,8 +87,7 @@ struct ioh_gpio_reg_data { * @gpio_use_sel: Save GPIO_USE_SEL1~4 register for PM * @ch: Indicate GPIO channel * @irq_base: Save base of IRQ number for interrupt - * @spinlock: Used for register access protection in - * interrupt context ioh_irq_type and PM; + * @spinlock: Used for register access protection */ struct ioh_gpio { void __iomem *base; @@ -97,7 +96,6 @@ struct ioh_gpio { struct gpio_chip gpio; struct ioh_gpio_reg_data ioh_gpio_reg; u32 gpio_use_sel; - struct mutex lock; int ch; int irq_base; spinlock_t spinlock; @@ -109,8 +107,9 @@ static void ioh_gpio_set(struct gpio_chip *gpio, unsigned nr, int val) { u32 reg_val; struct ioh_gpio *chip = container_of(gpio, struct ioh_gpio, gpio); + unsigned long flags; - mutex_lock(&chip->lock); + spin_lock_irqsave(&chip->spinlock, flags); reg_val = ioread32(&chip->reg->regs[chip->ch].po); if (val) reg_val |= (1 << nr); @@ -118,7 +117,7 @@ static void ioh_gpio_set(struct gpio_chip *gpio, unsigned nr, int val) reg_val &= ~(1 << nr); iowrite32(reg_val, &chip->reg->regs[chip->ch].po); - mutex_unlock(&chip->lock); + spin_unlock_irqrestore(&chip->spinlock, flags); } static int ioh_gpio_get(struct gpio_chip *gpio, unsigned nr) @@ -134,8 +133,9 @@ static int ioh_gpio_direction_output(struct gpio_chip *gpio, unsigned nr, struct ioh_gpio *chip = container_of(gpio, struct ioh_gpio, gpio); u32 pm; u32 reg_val; + unsigned long flags; - mutex_lock(&chip->lock); + spin_lock_irqsave(&chip->spinlock, flags); pm = ioread32(&chip->reg->regs[chip->ch].pm) & ((1 << num_ports[chip->ch]) - 1); pm |= (1 << nr); @@ -148,7 +148,7 @@ static int ioh_gpio_direction_output(struct gpio_chip *gpio, unsigned nr, reg_val &= ~(1 << nr); iowrite32(reg_val, &chip->reg->regs[chip->ch].po); - mutex_unlock(&chip->lock); + spin_unlock_irqrestore(&chip->spinlock, flags); return 0; } @@ -157,13 +157,14 @@ static int ioh_gpio_direction_input(struct gpio_chip *gpio, unsigned nr) { struct ioh_gpio *chip = container_of(gpio, struct ioh_gpio, gpio); u32 pm; + unsigned long flags; - mutex_lock(&chip->lock); + spin_lock_irqsave(&chip->spinlock, flags); pm = ioread32(&chip->reg->regs[chip->ch].pm) & ((1 << num_ports[chip->ch]) - 1); pm &= ~(1 << nr); iowrite32(pm, &chip->reg->regs[chip->ch].pm); - mutex_unlock(&chip->lock); + spin_unlock_irqrestore(&chip->spinlock, flags); return 0; } @@ -447,7 +448,6 @@ static int __devinit ioh_gpio_probe(struct pci_dev *pdev, chip->base = base; chip->reg = chip->base; chip->ch = i; - mutex_init(&chip->lock); spin_lock_init(&chip->spinlock); ioh_gpio_setup(chip, num_ports[i]); ret = gpiochip_add(&chip->gpio); -- 1.7.9.5