[PATCH v1 2/2] gpiolib: Check array_info for NULL only once in gpiod_get_array()

From: Andy Shevchenko
Date: Tue Mar 21 2023 - 09:54:29 EST


gpiod_get_array() has a long if-else-if branching where each of them
tests for the same variable to be not NULL. Instead, check for NULL
before even going to that flow.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/gpio/gpiolib.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 3e94990f1f90..ee24428c5fe3 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -4294,7 +4294,7 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
if (!descs)
return ERR_PTR(-ENOMEM);

- for (descs->ndescs = 0; descs->ndescs < count; ) {
+ for (descs->ndescs = 0; descs->ndescs < count; descs->ndescs++) {
desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
if (IS_ERR(desc)) {
gpiod_put_array(descs);
@@ -4339,8 +4339,13 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
count - descs->ndescs);
descs->info = array_info;
}
+
+ /* If there is no cache for fast bitmap processing path, continue */
+ if (!array_info)
+ continue;
+
/* Unmark array members which don't belong to the 'fast' chip */
- if (array_info && array_info->chip != gc) {
+ if (array_info->chip != gc) {
__clear_bit(descs->ndescs, array_info->get_mask);
__clear_bit(descs->ndescs, array_info->set_mask);
}
@@ -4348,8 +4353,7 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
* Detect array members which belong to the 'fast' chip
* but their pins are not in hardware order.
*/
- else if (array_info &&
- gpio_chip_hwgpio(desc) != descs->ndescs) {
+ else if (gpio_chip_hwgpio(desc) != descs->ndescs) {
/*
* Don't use fast path if all array members processed so
* far belong to the same chip as this one but its pin
@@ -4363,7 +4367,7 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
__clear_bit(descs->ndescs,
array_info->set_mask);
}
- } else if (array_info) {
+ } else {
/* Exclude open drain or open source from fast output */
if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
gpiochip_line_is_open_source(gc, descs->ndescs))
@@ -4374,8 +4378,6 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
__set_bit(descs->ndescs,
array_info->invert_mask);
}
-
- descs->ndescs++;
}
if (array_info)
dev_dbg(dev,
--
2.40.0.1.gaa8946217a0b