From 6f68f0ac72087c29a94d1736324902e3ec07a4ec Mon Sep 17 00:00:00 2001 From: Binoy Jayan Date: Wed, 14 Jun 2017 12:59:51 +0530 Subject: [PATCH] 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 Signed-off-by: Binoy Jayan Acked-by: Benjamin Tissoires Reviewed-by: David Herrmann Signed-off-by: Jiri Kosina --- drivers/hid/hid-core.c | 15 ++++----------- include/linux/hid.h | 3 +-- 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 */