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authorBinoy Jayan <binoy.jayan@linaro.org>2017-06-14 09:29:51 +0200
committerJiri Kosina <jkosina@suse.cz>2017-08-01 13:12:46 +0200
commit6f68f0ac72087c29a94d1736324902e3ec07a4ec (patch)
tree21eccc6ce85d005d4a669c55aee0638010cf2d02
parentMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jik... (diff)
downloadlinux-6f68f0ac72087c29a94d1736324902e3ec07a4ec.tar.xz
linux-6f68f0ac72087c29a94d1736324902e3ec07a4ec.zip
HID: Remove the semaphore driver_lock
The semaphore 'driver_lock' is used as a simple mutex, and also unnecessary as suggested by Arnd. Hence removing it, as the concurrency between the probe and remove is already handled in the driver core. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Binoy Jayan <binoy.jayan@linaro.org> Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
-rw-r--r--drivers/hid/hid-core.c15
-rw-r--r--include/linux/hid.h3
2 files changed, 5 insertions, 13 deletions
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 9017dcc14502..96e5457c2cc3 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2487,11 +2487,9 @@ static int hid_device_probe(struct device *dev)
const struct hid_device_id *id;
int ret = 0;
- if (down_interruptible(&hdev->driver_lock))
- return -EINTR;
if (down_interruptible(&hdev->driver_input_lock)) {
ret = -EINTR;
- goto unlock_driver_lock;
+ goto end;
}
hdev->io_started = false;
@@ -2518,8 +2516,7 @@ static int hid_device_probe(struct device *dev)
unlock:
if (!hdev->io_started)
up(&hdev->driver_input_lock);
-unlock_driver_lock:
- up(&hdev->driver_lock);
+end:
return ret;
}
@@ -2529,11 +2526,9 @@ static int hid_device_remove(struct device *dev)
struct hid_driver *hdrv;
int ret = 0;
- if (down_interruptible(&hdev->driver_lock))
- return -EINTR;
if (down_interruptible(&hdev->driver_input_lock)) {
ret = -EINTR;
- goto unlock_driver_lock;
+ goto end;
}
hdev->io_started = false;
@@ -2549,8 +2544,7 @@ static int hid_device_remove(struct device *dev)
if (!hdev->io_started)
up(&hdev->driver_input_lock);
-unlock_driver_lock:
- up(&hdev->driver_lock);
+end:
return ret;
}
@@ -3008,7 +3002,6 @@ struct hid_device *hid_allocate_device(void)
init_waitqueue_head(&hdev->debug_wait);
INIT_LIST_HEAD(&hdev->debug_list);
spin_lock_init(&hdev->debug_list_lock);
- sema_init(&hdev->driver_lock, 1);
sema_init(&hdev->driver_input_lock, 1);
mutex_init(&hdev->ll_open_lock);
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 5006f9b5d837..142409fc1ff3 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -526,7 +526,6 @@ struct hid_device { /* device report descriptor */
struct hid_report_enum report_enum[HID_REPORT_TYPES];
struct work_struct led_work; /* delayed LED worker */
- struct semaphore driver_lock; /* protects the current driver, except during input */
struct semaphore driver_input_lock; /* protects the current driver */
struct device dev; /* device */
struct hid_driver *driver;
@@ -551,7 +550,7 @@ struct hid_device { /* device report descriptor */
unsigned int status; /* see STAT flags above */
unsigned claimed; /* Claimed by hidinput, hiddev? */
unsigned quirks; /* Various quirks the device can pull on us */
- bool io_started; /* Protected by driver_lock. If IO has started */
+ bool io_started; /* If IO has started */
struct list_head inputs; /* The list of inputs */
void *hiddev; /* The hiddev structure */