Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752623AbdFMJZd (ORCPT ); Tue, 13 Jun 2017 05:25:33 -0400 Received: from mail-pf0-f180.google.com ([209.85.192.180]:32768 "EHLO mail-pf0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752021AbdFMJZc (ORCPT ); Tue, 13 Jun 2017 05:25:32 -0400 From: Binoy Jayan To: Binoy Jayan Cc: linux-kernel@vger.kernel.org, Arnd Bergmann , Rajendra , Mark Brown , Jiri Kosina , Benjamin Tissoires Subject: [PATCH v2] HID: Replace semaphore driver_lock with mutex Date: Tue, 13 Jun 2017 14:55:26 +0530 Message-Id: <1497345926-3262-1-git-send-email-binoy.jayan@linaro.org> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2638 Lines: 90 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. Signed-off-by: Binoy Jayan Suggested-by: Arnd Bergmann --- v1 --> v2 Removed driver_lock drivers/hid/hid-core.c | 15 ++++----------- include/linux/hid.h | 2 +- 2 files changed, 5 insertions(+), 12 deletions(-) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 04cee65..559533b 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -2225,11 +2225,9 @@ 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; @@ -2256,8 +2254,7 @@ 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; } @@ -2267,11 +2264,9 @@ 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; @@ -2287,8 +2282,7 @@ 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; } @@ -2745,7 +2739,6 @@ 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); return hdev; diff --git a/include/linux/hid.h b/include/linux/hid.h index 5be325d..1add2b3 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -516,7 +516,7 @@ 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 mutex 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; -- Binoy Jayan