| Message ID | a5d7b7ed45046ec6f7b5fbf9c284281e02204198.1490135047.git.julia@ni.com |
|---|---|
| State | New |
| Headers | show |
On Tue, Mar 21, 2017 at 05:43:09PM -0500, Julia Cartwright wrote: >The pci-idio-16 gpio driver currently implements an irq_chip for handling >interrupts; due to how irq_chip handling is done, it's necessary for the >irq_chip methods to be invoked from hardirq context, even on a a >real-time kernel. Because the spinlock_t type becomes a "sleeping" >spinlock w/ RT kernels, it is not suitable to be used with irq_chips. > >A quick audit of the operations under the lock reveal that they do only >minimal, bounded work, and are therefore safe to do under a raw spinlock. > >Signed-off-by: Julia Cartwright <julia@ni.com> Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> >--- >New patch as of v2 of series. > > drivers/gpio/gpio-pci-idio-16.c | 28 ++++++++++++++-------------- > 1 file changed, 14 insertions(+), 14 deletions(-) > >diff --git a/drivers/gpio/gpio-pci-idio-16.c b/drivers/gpio/gpio-pci-idio-16.c >index 269ab628634b..7de4f6a2cb49 100644 >--- a/drivers/gpio/gpio-pci-idio-16.c >+++ b/drivers/gpio/gpio-pci-idio-16.c >@@ -59,7 +59,7 @@ struct idio_16_gpio_reg { > */ > struct idio_16_gpio { > struct gpio_chip chip; >- spinlock_t lock; >+ raw_spinlock_t lock; > struct idio_16_gpio_reg __iomem *reg; > unsigned long irq_mask; > }; >@@ -121,7 +121,7 @@ static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset, > } else > base = &idio16gpio->reg->out0_7; > >- spin_lock_irqsave(&idio16gpio->lock, flags); >+ raw_spin_lock_irqsave(&idio16gpio->lock, flags); > > if (value) > out_state = ioread8(base) | mask; >@@ -130,7 +130,7 @@ static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset, > > iowrite8(out_state, base); > >- spin_unlock_irqrestore(&idio16gpio->lock, flags); >+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags); > } > > static void idio_16_gpio_set_multiple(struct gpio_chip *chip, >@@ -140,7 +140,7 @@ static void idio_16_gpio_set_multiple(struct gpio_chip *chip, > unsigned long flags; > unsigned int out_state; > >- spin_lock_irqsave(&idio16gpio->lock, flags); >+ raw_spin_lock_irqsave(&idio16gpio->lock, flags); > > /* process output lines 0-7 */ > if (*mask & 0xFF) { >@@ -160,7 +160,7 @@ static void idio_16_gpio_set_multiple(struct gpio_chip *chip, > iowrite8(out_state, &idio16gpio->reg->out8_15); > } > >- spin_unlock_irqrestore(&idio16gpio->lock, flags); >+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags); > } > > static void idio_16_irq_ack(struct irq_data *data) >@@ -177,11 +177,11 @@ static void idio_16_irq_mask(struct irq_data *data) > idio16gpio->irq_mask &= ~mask; > > if (!idio16gpio->irq_mask) { >- spin_lock_irqsave(&idio16gpio->lock, flags); >+ raw_spin_lock_irqsave(&idio16gpio->lock, flags); > > iowrite8(0, &idio16gpio->reg->irq_ctl); > >- spin_unlock_irqrestore(&idio16gpio->lock, flags); >+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags); > } > } > >@@ -196,11 +196,11 @@ static void idio_16_irq_unmask(struct irq_data *data) > idio16gpio->irq_mask |= mask; > > if (!prev_irq_mask) { >- spin_lock_irqsave(&idio16gpio->lock, flags); >+ raw_spin_lock_irqsave(&idio16gpio->lock, flags); > > ioread8(&idio16gpio->reg->irq_ctl); > >- spin_unlock_irqrestore(&idio16gpio->lock, flags); >+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags); > } > } > >@@ -229,11 +229,11 @@ static irqreturn_t idio_16_irq_handler(int irq, void *dev_id) > struct gpio_chip *const chip = &idio16gpio->chip; > int gpio; > >- spin_lock(&idio16gpio->lock); >+ raw_spin_lock(&idio16gpio->lock); > > irq_status = ioread8(&idio16gpio->reg->irq_status); > >- spin_unlock(&idio16gpio->lock); >+ raw_spin_unlock(&idio16gpio->lock); > > /* Make sure our device generated IRQ */ > if (!(irq_status & 0x3) || !(irq_status & 0x4)) >@@ -242,12 +242,12 @@ static irqreturn_t idio_16_irq_handler(int irq, void *dev_id) > for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio) > generic_handle_irq(irq_find_mapping(chip->irqdomain, gpio)); > >- spin_lock(&idio16gpio->lock); >+ raw_spin_lock(&idio16gpio->lock); > > /* Clear interrupt */ > iowrite8(0, &idio16gpio->reg->in0_7); > >- spin_unlock(&idio16gpio->lock); >+ raw_spin_unlock(&idio16gpio->lock); > > return IRQ_HANDLED; > } >@@ -302,7 +302,7 @@ static int idio_16_probe(struct pci_dev *pdev, const struct pci_device_id *id) > idio16gpio->chip.set = idio_16_gpio_set; > idio16gpio->chip.set_multiple = idio_16_gpio_set_multiple; > >- spin_lock_init(&idio16gpio->lock); >+ raw_spin_lock_init(&idio16gpio->lock); > > err = devm_gpiochip_add_data(dev, &idio16gpio->chip, idio16gpio); > if (err) { >-- >2.12.0 > -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Mar 21, 2017 at 11:43 PM, Julia Cartwright <julia@ni.com> wrote: > The pci-idio-16 gpio driver currently implements an irq_chip for handling > interrupts; due to how irq_chip handling is done, it's necessary for the > irq_chip methods to be invoked from hardirq context, even on a a > real-time kernel. Because the spinlock_t type becomes a "sleeping" > spinlock w/ RT kernels, it is not suitable to be used with irq_chips. > > A quick audit of the operations under the lock reveal that they do only > minimal, bounded work, and are therefore safe to do under a raw spinlock. > > Signed-off-by: Julia Cartwright <julia@ni.com> > --- > New patch as of v2 of series. Patch applied with William's ACK. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/gpio/gpio-pci-idio-16.c b/drivers/gpio/gpio-pci-idio-16.c index 269ab628634b..7de4f6a2cb49 100644 --- a/drivers/gpio/gpio-pci-idio-16.c +++ b/drivers/gpio/gpio-pci-idio-16.c @@ -59,7 +59,7 @@ struct idio_16_gpio_reg { */ struct idio_16_gpio { struct gpio_chip chip; - spinlock_t lock; + raw_spinlock_t lock; struct idio_16_gpio_reg __iomem *reg; unsigned long irq_mask; }; @@ -121,7 +121,7 @@ static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset, } else base = &idio16gpio->reg->out0_7; - spin_lock_irqsave(&idio16gpio->lock, flags); + raw_spin_lock_irqsave(&idio16gpio->lock, flags); if (value) out_state = ioread8(base) | mask; @@ -130,7 +130,7 @@ static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset, iowrite8(out_state, base); - spin_unlock_irqrestore(&idio16gpio->lock, flags); + raw_spin_unlock_irqrestore(&idio16gpio->lock, flags); } static void idio_16_gpio_set_multiple(struct gpio_chip *chip, @@ -140,7 +140,7 @@ static void idio_16_gpio_set_multiple(struct gpio_chip *chip, unsigned long flags; unsigned int out_state; - spin_lock_irqsave(&idio16gpio->lock, flags); + raw_spin_lock_irqsave(&idio16gpio->lock, flags); /* process output lines 0-7 */ if (*mask & 0xFF) { @@ -160,7 +160,7 @@ static void idio_16_gpio_set_multiple(struct gpio_chip *chip, iowrite8(out_state, &idio16gpio->reg->out8_15); } - spin_unlock_irqrestore(&idio16gpio->lock, flags); + raw_spin_unlock_irqrestore(&idio16gpio->lock, flags); } static void idio_16_irq_ack(struct irq_data *data) @@ -177,11 +177,11 @@ static void idio_16_irq_mask(struct irq_data *data) idio16gpio->irq_mask &= ~mask; if (!idio16gpio->irq_mask) { - spin_lock_irqsave(&idio16gpio->lock, flags); + raw_spin_lock_irqsave(&idio16gpio->lock, flags); iowrite8(0, &idio16gpio->reg->irq_ctl); - spin_unlock_irqrestore(&idio16gpio->lock, flags); + raw_spin_unlock_irqrestore(&idio16gpio->lock, flags); } } @@ -196,11 +196,11 @@ static void idio_16_irq_unmask(struct irq_data *data) idio16gpio->irq_mask |= mask; if (!prev_irq_mask) { - spin_lock_irqsave(&idio16gpio->lock, flags); + raw_spin_lock_irqsave(&idio16gpio->lock, flags); ioread8(&idio16gpio->reg->irq_ctl); - spin_unlock_irqrestore(&idio16gpio->lock, flags); + raw_spin_unlock_irqrestore(&idio16gpio->lock, flags); } } @@ -229,11 +229,11 @@ static irqreturn_t idio_16_irq_handler(int irq, void *dev_id) struct gpio_chip *const chip = &idio16gpio->chip; int gpio; - spin_lock(&idio16gpio->lock); + raw_spin_lock(&idio16gpio->lock); irq_status = ioread8(&idio16gpio->reg->irq_status); - spin_unlock(&idio16gpio->lock); + raw_spin_unlock(&idio16gpio->lock); /* Make sure our device generated IRQ */ if (!(irq_status & 0x3) || !(irq_status & 0x4)) @@ -242,12 +242,12 @@ static irqreturn_t idio_16_irq_handler(int irq, void *dev_id) for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio) generic_handle_irq(irq_find_mapping(chip->irqdomain, gpio)); - spin_lock(&idio16gpio->lock); + raw_spin_lock(&idio16gpio->lock); /* Clear interrupt */ iowrite8(0, &idio16gpio->reg->in0_7); - spin_unlock(&idio16gpio->lock); + raw_spin_unlock(&idio16gpio->lock); return IRQ_HANDLED; } @@ -302,7 +302,7 @@ static int idio_16_probe(struct pci_dev *pdev, const struct pci_device_id *id) idio16gpio->chip.set = idio_16_gpio_set; idio16gpio->chip.set_multiple = idio_16_gpio_set_multiple; - spin_lock_init(&idio16gpio->lock); + raw_spin_lock_init(&idio16gpio->lock); err = devm_gpiochip_add_data(dev, &idio16gpio->chip, idio16gpio); if (err) {
The pci-idio-16 gpio driver currently implements an irq_chip for handling interrupts; due to how irq_chip handling is done, it's necessary for the irq_chip methods to be invoked from hardirq context, even on a a real-time kernel. Because the spinlock_t type becomes a "sleeping" spinlock w/ RT kernels, it is not suitable to be used with irq_chips. A quick audit of the operations under the lock reveal that they do only minimal, bounded work, and are therefore safe to do under a raw spinlock. Signed-off-by: Julia Cartwright <julia@ni.com> --- New patch as of v2 of series. drivers/gpio/gpio-pci-idio-16.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-)