[PATCH v1] gpio: pca953x: Reduce stack usage in couple of functions

From: Andy Shevchenko
Date: Wed Oct 23 2019 - 11:31:03 EST


Simple bitmap operations are safe against in-place modifications.
Due to above we may get rid of temporary variables in some cases.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---

Andrew, it can be folded into "gpio: pca953x: Convert to use bitmap API"

drivers/gpio/gpio-pca953x.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index f80ed5a43614..b9e326dfed23 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -468,7 +468,6 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
{
struct pca953x_chip *chip = gpiochip_get_data(gc);
DECLARE_BITMAP(reg_val, MAX_LINE);
- DECLARE_BITMAP(new_val, MAX_LINE);
int ret;

mutex_lock(&chip->i2c_lock);
@@ -476,9 +475,9 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
if (ret)
goto exit;

- bitmap_replace(new_val, reg_val, bits, mask, gc->ngpio);
+ bitmap_replace(reg_val, reg_val, bits, mask, gc->ngpio);

- pca953x_write_regs(chip, chip->regs->output, new_val);
+ pca953x_write_regs(chip, chip->regs->output, reg_val);
exit:
mutex_unlock(&chip->i2c_lock);
}
@@ -605,7 +604,6 @@ static void pca953x_irq_bus_sync_unlock(struct irq_data *d)
struct pca953x_chip *chip = gpiochip_get_data(gc);
DECLARE_BITMAP(irq_mask, MAX_LINE);
DECLARE_BITMAP(reg_direction, MAX_LINE);
- DECLARE_BITMAP(new_irqs, MAX_LINE);
int level;

pca953x_read_regs(chip, chip->regs->direction, reg_direction);
@@ -620,8 +618,8 @@ static void pca953x_irq_bus_sync_unlock(struct irq_data *d)
pca953x_write_regs(chip, PCAL953X_INT_MASK, irq_mask);
}

- bitmap_or(new_irqs, chip->irq_trig_fall, chip->irq_trig_raise, gc->ngpio);
- bitmap_and(irq_mask, new_irqs, reg_direction, gc->ngpio);
+ bitmap_or(irq_mask, chip->irq_trig_fall, chip->irq_trig_raise, gc->ngpio);
+ bitmap_and(irq_mask, irq_mask, reg_direction, gc->ngpio);

/* Look for any newly setup interrupt */
for_each_set_bit(level, irq_mask, gc->ngpio)
--
2.23.0