openwrt/target/linux/generic/patches-4.4/864-gpiommc_configfs_lockin...

59 lines
1.3 KiB
Diff

The gpiommc configfs context structure needs locking, as configfs
does not lock access between files.
--- a/drivers/mmc/host/gpiommc.c
+++ b/drivers/mmc/host/gpiommc.c
@@ -144,6 +144,8 @@ struct gpiommc_configfs_device {
struct platform_device *pdev;
/* The configuration */
struct gpiommc_platform_data pdata;
+ /* Mutex to protect this structure */
+ struct mutex mutex;
};
#define GPIO_INVALID -1
@@ -234,6 +236,8 @@ static ssize_t gpiommc_config_attr_show(
unsigned int gpio;
int err = 0;
+ mutex_lock(&dev->mutex);
+
if (attr == &gpiommc_attr_DI) {
gpio = dev->pdata.pins.gpio_di;
if (gpio == GPIO_INVALID)
@@ -294,6 +298,8 @@ static ssize_t gpiommc_config_attr_show(
WARN_ON(1);
err = -ENOSYS;
out:
+ mutex_unlock(&dev->mutex);
+
return err ? err : count;
}
@@ -353,6 +359,8 @@ static ssize_t gpiommc_config_attr_store
int err = -EINVAL;
unsigned long data;
+ mutex_lock(&dev->mutex);
+
if (attr == &gpiommc_attr_register) {
err = kstrtoul(page, 10, &data);
if (err)
@@ -478,6 +486,8 @@ static ssize_t gpiommc_config_attr_store
WARN_ON(1);
err = -ENOSYS;
out:
+ mutex_unlock(&dev->mutex);
+
return err ? err : count;
}
@@ -514,6 +524,7 @@ static struct config_item *gpiommc_make_
if (!dev)
return NULL;
+ mutex_init(&dev->mutex);
config_item_init_type_name(&dev->item, name,
&gpiommc_dev_ci_type);