From: stefani@seibold.net
To: linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org,
oneukum@suse.de
Cc: alan@lxorguk.ukuu.org.uk, linux-usb@vger.kernel.org,
Stefani Seibold <stefani@seibold.net>
Subject: [PATCH 08/11] Handle a non blocking read without blocking
Date: Wed, 6 Jun 2012 18:27:09 +0200 [thread overview]
Message-ID: <1339000032-10313-9-git-send-email-stefani@seibold.net> (raw)
In-Reply-To: <1339000032-10313-1-git-send-email-stefani@seibold.net>
From: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Stefani Seibold <stefani@seibold.net>
---
drivers/usb/usb-skeleton.c | 11 ++++++++---
1 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c
index cab16e2..46c1bbb 100644
--- a/drivers/usb/usb-skeleton.c
+++ b/drivers/usb/usb-skeleton.c
@@ -241,9 +241,14 @@ static ssize_t skel_read(struct file *file, char *buffer, size_t count,
return 0;
/* no concurrent readers */
- retval = mutex_lock_interruptible(&dev->io_mutex);
- if (retval < 0)
- return retval;
+ if (file->f_flags & O_NONBLOCK) {
+ if (!mutex_trylock(&dev->io_mutex))
+ return -EAGAIN;
+ } else {
+ retval = mutex_lock_interruptible(&dev->io_mutex);
+ if (retval < 0)
+ return retval;
+ }
if (!dev->connected) { /* disconnect() was called */
retval = -ENODEV;
--
1.7.8.6
next prev parent reply other threads:[~2012-06-06 16:27 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-06 16:27 [PATCH] fix usb skeleton driver stefani
2012-06-06 16:27 ` [PATCH 01/11] fix wrong label in skel_open stefani
2012-06-06 18:52 ` Oliver Neukum
2012-06-06 19:59 ` Stefani Seibold
2012-06-06 16:27 ` [PATCH 02/11] code cleanup stefani
2012-06-06 18:57 ` Oliver Neukum
2012-06-06 16:27 ` [PATCH 03/11] remove dead code stefani
2012-06-06 16:27 ` [PATCH 04/11] remove usb_interface pointer stefani
2012-06-06 18:59 ` Oliver Neukum
2012-06-06 20:04 ` Stefani Seibold
2012-06-06 20:19 ` Alan Stern
2012-06-06 22:54 ` Greg KH
2012-06-07 8:07 ` Stefani Seibold
2012-06-07 11:51 ` Stefani Seibold
2012-06-07 14:28 ` Alan Stern
2012-06-07 15:03 ` Stefani Seibold
2012-06-07 15:27 ` Alan Stern
2012-06-07 19:50 ` Stefani Seibold
2012-06-07 20:42 ` Alan Stern
2012-06-08 7:18 ` RFC: remove usb_device pointer from usb_skeleton.c Stefani Seibold
2012-06-08 8:28 ` Oliver Neukum
2012-06-08 13:46 ` Alan Stern
2012-06-06 16:27 ` [PATCH 05/11] remove unneeded forward declaration stefani
2012-06-06 16:27 ` [PATCH 06/11] introduce fsync function stefani
2012-06-06 16:27 ` [PATCH 07/11] remove pr_err() noise in skel_open stefani
2012-06-06 16:27 ` stefani [this message]
2012-06-06 16:27 ` [PATCH 09/11] Synchronize disconnect() handler with open() and release(), to fix races stefani
2012-06-06 16:27 ` [PATCH 10/11] Introduce single user mode stefani
2012-06-06 16:27 ` [PATCH 11/11] Bump version number and add aditional author stefani
2012-06-06 16:55 ` [PATCH] fix usb skeleton driver Alan Stern
2012-06-06 17:53 ` Stefani Seibold
2012-06-06 18:16 ` Alan Stern
2012-06-06 20:19 ` Stefani Seibold
2012-06-06 20:22 ` Alan Stern
2012-06-07 8:13 ` Stefani Seibold
2012-06-07 7:10 ` Bjørn Mork
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