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Message-ID: <20260116081036.352286-10-tzungbi@kernel.org>
Date: Fri, 16 Jan 2026 08:10:22 +0000
From: Tzung-Bi Shih <tzungbi@...nel.org>
To: Benson Leung <bleung@...omium.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
"Rafael J . Wysocki" <rafael@...nel.org>,
Danilo Krummrich <dakr@...nel.org>,
Bartosz Golaszewski <brgl@...ev.pl>,
Linus Walleij <linusw@...nel.org>
Cc: Jonathan Corbet <corbet@....net>,
Shuah Khan <shuah@...nel.org>,
linux-doc@...r.kernel.org,
linux-kernel@...r.kernel.org,
chrome-platform@...ts.linux.dev,
linux-kselftest@...r.kernel.org,
tzungbi@...nel.org,
Laurent Pinchart <laurent.pinchart@...asonboard.com>,
Wolfram Sang <wsa+renesas@...g-engineering.com>,
Simona Vetter <simona.vetter@...ll.ch>,
Dan Williams <dan.j.williams@...el.com>,
Jason Gunthorpe <jgg@...dia.com>,
linux-gpio@...r.kernel.org
Subject: [PATCH 09/23] gpiolib: Ensure struct gpio_chip for gpiochip_setup_dev()
Ensure struct gpio_chip for gpiochip_setup_dev(). This eliminates a few
checks for struct gpio_chip.
Signed-off-by: Tzung-Bi Shih <tzungbi@...nel.org>
---
drivers/gpio/gpiolib-cdev.c | 13 ++-----------
drivers/gpio/gpiolib-cdev.h | 3 ++-
drivers/gpio/gpiolib-sysfs.c | 11 ++---------
drivers/gpio/gpiolib-sysfs.h | 5 +++--
drivers/gpio/gpiolib.c | 24 +++++++++++++++++-------
5 files changed, 26 insertions(+), 30 deletions(-)
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 66bd260c68e9..24449bbe38c9 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -2784,9 +2784,9 @@ static const struct file_operations gpio_fileops = {
#endif
};
-int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt)
+int gpiolib_cdev_register(struct gpio_device *gdev, struct gpio_chip *gc,
+ dev_t devt)
{
- struct gpio_chip *gc;
int ret;
cdev_init(&gdev->chrdev, &gpio_fileops);
@@ -2802,18 +2802,9 @@ int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt)
if (ret)
goto err_free_workqueue;
- guard(srcu)(&gdev->srcu);
- gc = srcu_dereference(gdev->chip, &gdev->srcu);
- if (!gc) {
- ret = -ENODEV;
- goto err_free_cdev;
- }
-
gpiochip_dbg(gc, "added GPIO chardev (%d:%d)\n", MAJOR(devt), gdev->id);
return 0;
-err_free_cdev:
- cdev_device_del(&gdev->chrdev, &gdev->dev);
err_free_workqueue:
destroy_workqueue(gdev->line_state_wq);
return ret;
diff --git a/drivers/gpio/gpiolib-cdev.h b/drivers/gpio/gpiolib-cdev.h
index b42644cbffb8..16ef1e2e96a0 100644
--- a/drivers/gpio/gpiolib-cdev.h
+++ b/drivers/gpio/gpiolib-cdev.h
@@ -7,7 +7,8 @@
struct gpio_device;
-int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt);
+int gpiolib_cdev_register(struct gpio_device *gdev, struct gpio_chip *gc,
+ dev_t devt);
void gpiolib_cdev_unregister(struct gpio_device *gdev);
#endif /* GPIOLIB_CDEV_H */
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 8e6b09d8b559..a4427a5cfa85 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -978,10 +978,9 @@ void gpiod_unexport(struct gpio_desc *desc)
}
EXPORT_SYMBOL_GPL(gpiod_unexport);
-int gpiochip_sysfs_register(struct gpio_device *gdev)
+int gpiochip_sysfs_register(struct gpio_device *gdev, struct gpio_chip *chip)
{
struct gpiodev_data *data;
- struct gpio_chip *chip;
struct device *parent;
int err;
@@ -994,12 +993,6 @@ int gpiochip_sysfs_register(struct gpio_device *gdev)
if (!class_is_registered(&gpio_class))
return 0;
- guard(srcu)(&gdev->srcu);
-
- chip = srcu_dereference(gdev->chip, &gdev->srcu);
- if (!chip)
- return -ENODEV;
-
/*
* For sysfs backward compatibility we need to preserve this
* preferred parenting to the gpio_chip parent field, if set.
@@ -1082,7 +1075,7 @@ static int gpiofind_sysfs_register(struct gpio_chip *gc, const void *data)
struct gpio_device *gdev = gc->gpiodev;
int ret;
- ret = gpiochip_sysfs_register(gdev);
+ ret = gpiochip_sysfs_register(gdev, gc);
if (ret)
gpiochip_err(gc, "failed to register the sysfs entry: %d\n", ret);
diff --git a/drivers/gpio/gpiolib-sysfs.h b/drivers/gpio/gpiolib-sysfs.h
index 93debe8e118c..192b1ee041a6 100644
--- a/drivers/gpio/gpiolib-sysfs.h
+++ b/drivers/gpio/gpiolib-sysfs.h
@@ -7,13 +7,14 @@ struct gpio_device;
#ifdef CONFIG_GPIO_SYSFS
-int gpiochip_sysfs_register(struct gpio_device *gdev);
+int gpiochip_sysfs_register(struct gpio_device *gdev, struct gpio_chip *chip);
void gpiochip_sysfs_unregister(struct gpio_device *gdev,
struct gpio_chip *chip);
#else
-static inline int gpiochip_sysfs_register(struct gpio_device *gdev)
+static inline int gpiochip_sysfs_register(struct gpio_device *gdev,
+ struct gpio_chip *chip)
{
return 0;
}
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index c3e1465042c4..efe72b81e131 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -882,14 +882,15 @@ static const struct device_type gpio_dev_type = {
};
#ifdef CONFIG_GPIO_CDEV
-#define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt))
+#define gcdev_register(gdev, gc, devt) \
+ gpiolib_cdev_register((gdev), (gc), (devt))
#define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev))
#else
/*
* gpiolib_cdev_register() indirectly calls device_add(), which is still
* required even when cdev is not selected.
*/
-#define gcdev_register(gdev, devt) device_add(&(gdev)->dev)
+#define gcdev_register(gdev, gc, devt) device_add(&(gdev)->dev)
#define gcdev_unregister(gdev) device_del(&(gdev)->dev)
#endif
@@ -897,7 +898,7 @@ static const struct device_type gpio_dev_type = {
* An initial reference count has been held in gpiochip_add_data_with_key().
* The caller should drop the reference via gpio_device_put() on errors.
*/
-static int gpiochip_setup_dev(struct gpio_device *gdev)
+static int gpiochip_setup_dev(struct gpio_device *gdev, struct gpio_chip *gc)
{
struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
int ret;
@@ -911,11 +912,11 @@ static int gpiochip_setup_dev(struct gpio_device *gdev)
if (fwnode && !fwnode->dev)
fwnode_dev_initialized(fwnode, false);
- ret = gcdev_register(gdev, gpio_devt);
+ ret = gcdev_register(gdev, gc, gpio_devt);
if (ret)
return ret;
- ret = gpiochip_sysfs_register(gdev);
+ ret = gpiochip_sysfs_register(gdev, gc);
if (ret)
goto err_remove_device;
@@ -962,13 +963,22 @@ static void machine_gpiochip_add(struct gpio_chip *gc)
static void gpiochip_setup_devs(void)
{
struct gpio_device *gdev;
+ struct gpio_chip *gc;
int ret;
guard(srcu)(&gpio_devices_srcu);
list_for_each_entry_srcu(gdev, &gpio_devices, list,
srcu_read_lock_held(&gpio_devices_srcu)) {
- ret = gpiochip_setup_dev(gdev);
+ guard(srcu)(&gdev->srcu);
+
+ gc = srcu_dereference(gdev->chip, &gdev->srcu);
+ if (!gc) {
+ dev_err(&gdev->dev, "Underlying GPIO chip is gone\n");
+ continue;
+ }
+
+ ret = gpiochip_setup_dev(gdev, gc);
if (ret) {
gpio_device_put(gdev);
dev_err(&gdev->dev,
@@ -1222,7 +1232,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
* (i.e., `gpio_bus_type` is ready). Otherwise, defer until later.
*/
if (gpiolib_initialized) {
- ret = gpiochip_setup_dev(gdev);
+ ret = gpiochip_setup_dev(gdev, gc);
if (ret)
goto err_teardown_shared;
}
--
2.52.0.457.g6b5491de43-goog
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