Re: [PATCH 1/4] gpio: gpiolib: Allow GPIO IRQs to lazy disable

From: Marc Zyngier
Date: Sat May 23 2020 - 05:43:08 EST


On 2020-05-22 14:19, Maulik Shah wrote:
With 'commit 461c1a7d4733 ("gpiolib: override irq_enable/disable")' gpiolib
overrides irqchip's irq_enable and irq_disable callbacks. If irq_disable
callback is implemented then genirq takes unlazy path to disable irq.

Underlying irqchip may not want to implement irq_disable callback to lazy
disable irq when client drivers invokes disable_irq(). By overriding
irq_disable callback, gpiolib ends up always unlazy disabling IRQ.

Allow gpiolib to lazy disable IRQs by overriding irq_disable callback only
if irqchip implemented irq_disable. In cases where irq_disable is not
implemented irq_mask is overridden. Similarly override irq_enable callback
only if irqchip implemented irq_enable otherwise irq_unmask is overridden.

Fixes: 461c1a7d47 (gpiolib: override irq_enable/disable)
Signed-off-by: Maulik Shah <mkshah@xxxxxxxxxxxxxx>
---
drivers/gpio/gpiolib.c | 59 +++++++++++++++++++++++++++++----------------
include/linux/gpio/driver.h | 13 ++++++++++
2 files changed, 51 insertions(+), 21 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index eaa0e20..a8fdc74 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2465,33 +2465,38 @@ static void gpiochip_irq_relres(struct irq_data *d)
gpiochip_relres_irq(gc, d->hwirq);
}

+static void gpiochip_irq_mask(struct irq_data *d)
+{
+ struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
+
+ if (chip->irq.irq_mask)
+ chip->irq.irq_mask(d);
+ gpiochip_disable_irq(chip, d->hwirq);
+}
+
+static void gpiochip_irq_unmask(struct irq_data *d)
+{
+ struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
+
+ gpiochip_enable_irq(chip, d->hwirq);
+ if (chip->irq.irq_unmask)
+ chip->irq.irq_unmask(d);
+}
+
static void gpiochip_irq_enable(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);

- gpiochip_enable_irq(gc, d->hwirq);
- if (gc->irq.irq_enable)
- gc->irq.irq_enable(d);
- else
- gc->irq.chip->irq_unmask(d);
+ gpiochip_enable_irq(chip, d->hwirq);

You really never compiled this, did you?

I've stopped looking at this. Please send something that you will have actually tested.

M.
--
Jazz is not dead. It just smells funny...