From d21c95c569c462da20d491b75d0a45bd70ddc1bf Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Fri, 16 May 2008 13:40:30 -0600 Subject: 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 --- drivers/char/cs5535_gpio.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/char/cs5535_gpio.c') 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); -- cgit v1.2.3 From f2b9857eee17797541b845782ade4d7a9d50f843 Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Sun, 18 May 2008 15:32:43 -0600 Subject: Add a bunch of cycle_kernel_lock() calls All of the open() functions which don't need the BKL on their face may still depend on its acquisition to serialize opens against driver initialization. So make those functions acquire then release the BKL to be on the safe side. Signed-off-by: Jonathan Corbet --- drivers/char/cs5535_gpio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/char/cs5535_gpio.c') diff --git a/drivers/char/cs5535_gpio.c b/drivers/char/cs5535_gpio.c index 628e3d3249d..04ba906b488 100644 --- a/drivers/char/cs5535_gpio.c +++ b/drivers/char/cs5535_gpio.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include @@ -153,12 +154,11 @@ 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); + cycle_kernel_lock(); /* the mask says which pins are usable by this driver */ if ((mask & (1 << m)) == 0) return -EINVAL; -- cgit v1.2.3