From: Founder Fang <founder.fang@gmail.com>
Date: Wed, 21 Nov 2012 07:20:31 +0000 (+0800)
Subject: HID: hidraw: fix nonblock read return EAGAIN after device removed
X-Git-Tag: v3.8-rc1~130^2^2~1
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=7611e8d26d8dd0e5e132b46e905cb579daf9da1e;p=~emulex%2Finfiniband.git

HID: hidraw: fix nonblock read return EAGAIN after device removed

When nonblock read the condition check (file->f_flags & O_NONBLOCK) always be
true, signal_pending and device exist checking never get a chance to run, so
the user mode code always get EAGAIN even if device removed. move nonblock mode
checking to the last can fix this problem.

Signed-off-by: Founder Fang <founder.fang@gmail.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
---

diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
index 7c47fc3f7b2..1d8c0219117 100644
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -57,10 +57,6 @@ static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count,
 			set_current_state(TASK_INTERRUPTIBLE);
 
 			while (list->head == list->tail) {
-				if (file->f_flags & O_NONBLOCK) {
-					ret = -EAGAIN;
-					break;
-				}
 				if (signal_pending(current)) {
 					ret = -ERESTARTSYS;
 					break;
@@ -69,6 +65,10 @@ static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count,
 					ret = -EIO;
 					break;
 				}
+				if (file->f_flags & O_NONBLOCK) {
+					ret = -EAGAIN;
+					break;
+				}
 
 				/* allow O_NONBLOCK to work well from other threads */
 				mutex_unlock(&list->read_mutex);