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authorJonathan Corbet <corbet@lwn.net>2008-05-16 13:40:30 -0600
committerJonathan Corbet <corbet@lwn.net>2008-06-20 14:05:50 -0600
commitd21c95c569c462da20d491b75d0a45bd70ddc1bf (patch)
treec5efcd4a1ae50101a56abc1f5a27ef5173da209d /drivers/char
parent39d95b9d857ad9ed335dd1a2d6c6de1f1ee69ce1 (diff)
Add "no BKL needed" comments to several drivers
This documents the fact that somebody looked at the relevant open() functions and concluded that, due to their trivial nature, no locking was needed. Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/cs5535_gpio.c2
-rw-r--r--drivers/char/dtlk.c2
-rw-r--r--drivers/char/pc8736x_gpio.c1
-rw-r--r--drivers/char/ppdev.c1
-rw-r--r--drivers/char/scx200_gpio.c1
-rw-r--r--drivers/char/tb0219.c1
-rw-r--r--drivers/char/vr41xx_giu.c2
7 files changed, 10 insertions, 0 deletions
diff --git a/drivers/char/cs5535_gpio.c b/drivers/char/cs5535_gpio.c
index c0a4a0bb509..628e3d3249d 100644
--- a/drivers/char/cs5535_gpio.c
+++ b/drivers/char/cs5535_gpio.c
@@ -153,6 +153,8 @@ static ssize_t cs5535_gpio_read(struct file *file, char __user *buf,
return count;
}
+/* No BKL needed here - "mask" is the only global resource used
+ here and it's a boot-time parameter */
static int cs5535_gpio_open(struct inode *inode, struct file *file)
{
u32 m = iminor(inode);
diff --git a/drivers/char/dtlk.c b/drivers/char/dtlk.c
index abde6ddefe6..433388c6023 100644
--- a/drivers/char/dtlk.c
+++ b/drivers/char/dtlk.c
@@ -288,6 +288,8 @@ static int dtlk_ioctl(struct inode *inode,
}
}
+/* No BKL needed here; "dtlk_busy" is the only global resource,
+ and it is not ever set by anybody (test is broken) */
static int dtlk_open(struct inode *inode, struct file *file)
{
TRACE_TEXT("(dtlk_open");
diff --git a/drivers/char/pc8736x_gpio.c b/drivers/char/pc8736x_gpio.c
index ecfaf180e5b..8715dc9f4a5 100644
--- a/drivers/char/pc8736x_gpio.c
+++ b/drivers/char/pc8736x_gpio.c
@@ -212,6 +212,7 @@ static struct nsc_gpio_ops pc8736x_gpio_ops = {
.gpio_current = pc8736x_gpio_current
};
+/* No BKL needed here; no global resources accessed */
static int pc8736x_gpio_open(struct inode *inode, struct file *file)
{
unsigned m = iminor(inode);
diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c
index 3aab837d948..ce198757488 100644
--- a/drivers/char/ppdev.c
+++ b/drivers/char/ppdev.c
@@ -633,6 +633,7 @@ static int pp_ioctl(struct inode *inode, struct file *file,
return 0;
}
+/* No BKL needed here: only local resources used */
static int pp_open (struct inode * inode, struct file * file)
{
unsigned int minor = iminor(inode);
diff --git a/drivers/char/scx200_gpio.c b/drivers/char/scx200_gpio.c
index 99e5272e3c5..be2c623a986 100644
--- a/drivers/char/scx200_gpio.c
+++ b/drivers/char/scx200_gpio.c
@@ -46,6 +46,7 @@ struct nsc_gpio_ops scx200_gpio_ops = {
};
EXPORT_SYMBOL_GPL(scx200_gpio_ops);
+/* No BKL needed here: no global resources used */
static int scx200_gpio_open(struct inode *inode, struct file *file)
{
unsigned m = iminor(inode);
diff --git a/drivers/char/tb0219.c b/drivers/char/tb0219.c
index 4c431cb7cf1..db8c2ca2ce4 100644
--- a/drivers/char/tb0219.c
+++ b/drivers/char/tb0219.c
@@ -232,6 +232,7 @@ static ssize_t tanbac_tb0219_write(struct file *file, const char __user *data,
return i;
}
+/* No BKL needed here; no global resources accessed */
static int tanbac_tb0219_open(struct inode *inode, struct file *file)
{
unsigned int minor;
diff --git a/drivers/char/vr41xx_giu.c b/drivers/char/vr41xx_giu.c
index e5ed09192be..412937fdb95 100644
--- a/drivers/char/vr41xx_giu.c
+++ b/drivers/char/vr41xx_giu.c
@@ -543,6 +543,8 @@ static ssize_t gpio_write(struct file *file, const char __user *data,
return i;
}
+/* No BKL needed here; only global (giu_nr_pins) is only set
+ at probe time */
static int gpio_open(struct inode *inode, struct file *file)
{
unsigned int pin;