summaryrefslogtreecommitdiff
path: root/drivers/usb/gadget/printer.c
diff options
context:
space:
mode:
authorArnd Bergmann <arnd@arndb.de>2010-07-11 23:18:56 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-10 14:35:39 -0700
commit925ce689bb31960c839804c19ef38d676f1939b9 (patch)
tree620c9b0f054a613d86aaa62901f93019856de0f9 /drivers/usb/gadget/printer.c
parent7c7e2d00435bd8129c4bacb73fe4a2d4db4e7d7c (diff)
USB: autoconvert trivial BKL users to private mutex
All these files use the big kernel lock in a trivial way to serialize their private file operations, typically resulting from an earlier semi-automatic pushdown from VFS. None of these drivers appears to want to lock against other code, and they all use the BKL as the top-level lock in their file operations, meaning that there is no lock-order inversion problem. Consequently, we can remove the BKL completely, replacing it with a per-file mutex in every case. Using a scripted approach means we can avoid typos. file=$1 name=$2 if grep -q lock_kernel ${file} ; then if grep -q 'include.*linux.mutex.h' ${file} ; then sed -i '/include.*<linux\/smp_lock.h>/d' ${file} else sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file} fi sed -i ${file} \ -e "/^#include.*linux.mutex.h/,$ { 1,/^\(static\|int\|long\)/ { /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex); } }" \ -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \ -e '/[ ]*cycle_kernel_lock();/d' else sed -i -e '/include.*\<smp_lock.h\>/d' ${file} \ -e '/cycle_kernel_lock()/d' fi Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/gadget/printer.c')
-rw-r--r--drivers/usb/gadget/printer.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/usb/gadget/printer.c b/drivers/usb/gadget/printer.c
index 88f05996aa02..cf241c371a71 100644
--- a/drivers/usb/gadget/printer.c
+++ b/drivers/usb/gadget/printer.c
@@ -25,7 +25,7 @@
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/timer.h>
@@ -70,6 +70,7 @@
#define DRIVER_DESC "Printer Gadget"
#define DRIVER_VERSION "2007 OCT 06"
+static DEFINE_MUTEX(printer_mutex);
static const char shortname [] = "printer";
static const char driver_desc [] = DRIVER_DESC;
@@ -476,7 +477,7 @@ printer_open(struct inode *inode, struct file *fd)
unsigned long flags;
int ret = -EBUSY;
- lock_kernel();
+ mutex_lock(&printer_mutex);
dev = container_of(inode->i_cdev, struct printer_dev, printer_cdev);
spin_lock_irqsave(&dev->lock, flags);
@@ -492,7 +493,7 @@ printer_open(struct inode *inode, struct file *fd)
spin_unlock_irqrestore(&dev->lock, flags);
DBG(dev, "printer_open returned %x\n", ret);
- unlock_kernel();
+ mutex_unlock(&printer_mutex);
return ret;
}