From: Geert Uytterhoeven <geert+renesas@glider.be>
To: Linus Walleij <linus.walleij@linaro.org>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH] gpio: of: Optimize quirk checks
Date: Fri, 29 Mar 2019 09:42:29 +0100 [thread overview]
Message-ID: <20190329084229.17018-1-geert+renesas@glider.be> (raw)
Simple string comparisons are cheaper than DT lookups, as the latter
involve taking a spinlock and traversing properties.
Hence optimize quirk checks by postponing DT lookups after string
comparisons.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
drivers/gpio/gpiolib-of.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 6a3ec575a404ed9f..3a6bb53d89dfed32 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -86,9 +86,9 @@ static void of_gpio_flags_quirks(struct device_node *np,
if (IS_ENABLED(CONFIG_REGULATOR) &&
(of_device_is_compatible(np, "regulator-fixed") ||
of_device_is_compatible(np, "reg-fixed-voltage") ||
- (of_device_is_compatible(np, "regulator-gpio") &&
- !(strcmp(propname, "enable-gpio") &&
- strcmp(propname, "enable-gpios"))))) {
+ (!(strcmp(propname, "enable-gpio") &&
+ strcmp(propname, "enable-gpios")) &&
+ of_device_is_compatible(np, "regulator-gpio")))) {
/*
* The regulator GPIO handles are specified such that the
* presence or absence of "enable-active-high" solely controls
@@ -119,9 +119,8 @@ static void of_gpio_flags_quirks(struct device_node *np,
* property named "cs-gpios" we need to inspect the child node
* to determine if the flags should have inverted semantics.
*/
- if (IS_ENABLED(CONFIG_SPI_MASTER) &&
- of_property_read_bool(np, "cs-gpios") &&
- !strcmp(propname, "cs-gpios")) {
+ if (IS_ENABLED(CONFIG_SPI_MASTER) && !strcmp(propname, "cs-gpios") &&
+ of_property_read_bool(np, "cs-gpios")) {
struct device_node *child;
u32 cs;
int ret;
--
2.17.1
next reply other threads:[~2019-03-29 8:42 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-29 8:42 Geert Uytterhoeven [this message]
2019-03-29 10:02 ` [PATCH] gpio: of: Optimize quirk checks Mukesh Ojha
2019-04-08 11:04 ` Linus Walleij
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