From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aniroop Mathur Subject: [PATCH] Input: evdev - add ioctl cmd EVIOCGBUFSIZE to get buffer size Date: Fri, 08 Jan 2016 20:53:08 +0530 Message-ID: <1452266588-3139-1-git-send-email-a.mathur@samsung.com> Return-path: Received: from mailout3.samsung.com ([203.254.224.33]:54816 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751167AbcAHPXl (ORCPT ); Fri, 8 Jan 2016 10:23:41 -0500 Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: dmitry.torokhov@gmail.com Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, aniroop.mathur@gmail.com, Aniroop Mathur Add ioctl cmd EVIOCGBUFSIZE to get kernel buffer size of device so that clients can accordingly set the size of userspace buffer and can know maximum number of events that they are required to read in worst case. Signed-off-by: Aniroop Mathur --- drivers/input/evdev.c | 3 +++ include/uapi/linux/input.h | 2 ++ 2 files changed, 5 insertions(+) diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index e9ae3d5..8b16f08 100644 --- a/drivers/input/evdev.c +++ b/drivers/input/evdev.c @@ -1103,6 +1103,9 @@ static long evdev_do_ioctl(struct file *file, unsigned int cmd, return 0; + case EVIOCGBUFSIZE: + return put_user(client->bufsize, (unsigned int __user *)p); + case EVIOCRMFF: return input_ff_erase(dev, (int)(unsigned long) p, file); diff --git a/include/uapi/linux/input.h b/include/uapi/linux/input.h index 2758687..51d66aa 100644 --- a/include/uapi/linux/input.h +++ b/include/uapi/linux/input.h @@ -114,6 +114,8 @@ struct input_mask { #define EVIOCSKEYCODE _IOW('E', 0x04, unsigned int[2]) /* set keycode */ #define EVIOCSKEYCODE_V2 _IOW('E', 0x04, struct input_keymap_entry) +#define EVIOCGBUFSIZE _IOR('E', 0x05, unsigned int) /* get device buffer size */ + #define EVIOCGNAME(len) _IOC(_IOC_READ, 'E', 0x06, len) /* get device name */ #define EVIOCGPHYS(len) _IOC(_IOC_READ, 'E', 0x07, len) /* get physical location */ #define EVIOCGUNIQ(len) _IOC(_IOC_READ, 'E', 0x08, len) /* get unique identifier */ -- 1.7.9.5