diff mbox series

raw/cnxk_gpio: allow controlling existing GPIO

Message ID 20220604140323.3380810-1-tduszynski@marvell.com (mailing list archive)
State Accepted, archived
Delegated to: Thomas Monjalon
Headers
Series raw/cnxk_gpio: allow controlling existing GPIO |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/iol-mellanox-Performance success Performance Testing PASS
ci/iol-intel-Performance success Performance Testing PASS
ci/iol-intel-Functional success Functional Testing PASS
ci/github-robot: build success github build: passed
ci/iol-aarch64-compile-testing success Testing PASS
ci/iol-aarch64-unit-testing success Testing PASS
ci/iol-x86_64-compile-testing success Testing PASS
ci/iol-x86_64-unit-testing success Testing PASS
ci/Intel-compilation success Compilation OK
ci/intel-Testing success Testing PASS
ci/iol-abi-testing success Testing PASS

Commit Message

Tomasz Duszynski June 4, 2022, 2:03 p.m. UTC 
  Controlling existing GPIO should be normally frowned upon because
we want to avoid situation where multiple contenders modify GPIO
state simultaneously.

Still there might be situations where this is actually needed.
Restarting killed application being an example here.

So relax current restrictions and respect user needs.

Signed-off-by: Tomasz Duszynski <tduszynski@marvell.com>
---
 drivers/raw/cnxk_gpio/cnxk_gpio.c | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

Comments

Thomas Monjalon June 8, 2022, 9:03 a.m. UTC | #1 
04/06/2022 16:03, Tomasz Duszynski:
> Controlling existing GPIO should be normally frowned upon because
> we want to avoid situation where multiple contenders modify GPIO
> state simultaneously.
> 
> Still there might be situations where this is actually needed.
> Restarting killed application being an example here.
> 
> So relax current restrictions and respect user needs.
> 
> Signed-off-by: Tomasz Duszynski <tduszynski@marvell.com>

Applied, thanks.
diff mbox series

Patch

diff --git a/drivers/raw/cnxk_gpio/cnxk_gpio.c b/drivers/raw/cnxk_gpio/cnxk_gpio.c
index 9577753851..d759ed82d4 100644
--- a/drivers/raw/cnxk_gpio/cnxk_gpio.c
+++ b/drivers/raw/cnxk_gpio/cnxk_gpio.c
@@ -4,6 +4,7 @@ 
 
 #include <dirent.h>
 #include <string.h>
+#include <sys/stat.h>
 
 #include <rte_bus_vdev.h>
 #include <rte_eal.h>
@@ -277,6 +278,17 @@  cnxk_gpio_lookup(struct cnxk_gpiochip *gpiochip, uint16_t queue)
 	return gpiochip->gpios[gpio];
 }
 
+static bool
+cnxk_gpio_exists(int num)
+{
+	char buf[CNXK_GPIO_BUFSZ];
+	struct stat st;
+
+	snprintf(buf, sizeof(buf), "%s/gpio%d", CNXK_GPIO_CLASS_PATH, num);
+
+	return !stat(buf, &st);
+}
+
 static int
 cnxk_gpio_queue_setup(struct rte_rawdev *dev, uint16_t queue_id,
 		      rte_rawdev_obj_t queue_conf, size_t queue_conf_size)
@@ -304,11 +316,15 @@  cnxk_gpio_queue_setup(struct rte_rawdev *dev, uint16_t queue_id,
 	gpio->num = num + gpiochip->base;
 	gpio->gpiochip = gpiochip;
 
-	snprintf(buf, sizeof(buf), "%s/export", CNXK_GPIO_CLASS_PATH);
-	ret = cnxk_gpio_write_attr_int(buf, gpio->num);
-	if (ret) {
-		rte_free(gpio);
-		return ret;
+	if (!cnxk_gpio_exists(gpio->num)) {
+		snprintf(buf, sizeof(buf), "%s/export", CNXK_GPIO_CLASS_PATH);
+		ret = cnxk_gpio_write_attr_int(buf, gpio->num);
+		if (ret) {
+			rte_free(gpio);
+			return ret;
+		}
+	} else {
+		RTE_LOG(WARNING, PMD, "using existing gpio%d\n", gpio->num);
 	}
 
 	gpiochip->gpios[num] = gpio;