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authorDavid John <davidjon@xenontk.org>2008-10-23 13:55:56 +0530
committerJonathan Corbet <corbet@lwn.net>2009-01-08 16:44:03 -0700
commit048cd5888f81713af4597bde5815f32d58fdf5b0 (patch)
tree87cd68ac3c852adb32170c73294fadaa54968620
parent4a6908a3a050aacc9c3a2f36b276b46c0629ad91 (diff)
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RTC: Remove the BKL.
Remove calls to the BKL since concurrent access is protected by the spin lock rtc_lock. Signed-off-by: David John <davidjon@xenontk.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
-rw-r--r--drivers/char/rtc.c17
1 files changed, 4 insertions, 13 deletions
diff --git a/drivers/char/rtc.c b/drivers/char/rtc.c
index 20d6efb6324..e0d0f8b2696 100644
--- a/drivers/char/rtc.c
+++ b/drivers/char/rtc.c
@@ -48,9 +48,10 @@
* CONFIG_HPET_EMULATE_RTC
* 1.12a Maciej W. Rozycki: Handle memory-mapped chips properly.
* 1.12ac Alan Cox: Allow read access to the day of week register
+ * 1.12b David John: Remove calls to the BKL.
*/
-#define RTC_VERSION "1.12ac"
+#define RTC_VERSION "1.12b"
/*
* Note that *all* calls to CMOS_READ and CMOS_WRITE are done with
@@ -73,7 +74,6 @@
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
-#include <linux/smp_lock.h>
#include <linux/sysctl.h>
#include <linux/wait.h>
#include <linux/bcd.h>
@@ -182,8 +182,8 @@ static int rtc_proc_open(struct inode *inode, struct file *file);
/*
* rtc_status is never changed by rtc_interrupt, and ioctl/open/close is
- * protected by the big kernel lock. However, ioctl can still disable the timer
- * in rtc_status and then with del_timer after the interrupt has read
+ * protected by the spin lock rtc_lock. However, ioctl can still disable the
+ * timer in rtc_status and then with del_timer after the interrupt has read
* rtc_status but before mod_timer is called, which would then reenable the
* timer (but you would need to have an awful timing before you'd trip on it)
*/
@@ -720,9 +720,7 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
long ret;
- lock_kernel();
ret = rtc_do_ioctl(cmd, arg, 0);
- unlock_kernel();
return ret;
}
@@ -731,12 +729,8 @@ static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
* Also clear the previous interrupt data on an open, and clean
* up things on a close.
*/
-
-/* We use rtc_lock to protect against concurrent opens. So the BKL is not
- * needed here. Or anywhere else in this driver. */
static int rtc_open(struct inode *inode, struct file *file)
{
- lock_kernel();
spin_lock_irq(&rtc_lock);
if (rtc_status & RTC_IS_OPEN)
@@ -746,12 +740,10 @@ static int rtc_open(struct inode *inode, struct file *file)
rtc_irq_data = 0;
spin_unlock_irq(&rtc_lock);
- unlock_kernel();
return 0;
out_busy:
spin_unlock_irq(&rtc_lock);
- unlock_kernel();
return -EBUSY;
}
@@ -800,7 +792,6 @@ no_irq:
}
#ifdef RTC_IRQ
-/* Called without the kernel lock - fine */
static unsigned int rtc_poll(struct file *file, poll_table *wait)
{
unsigned long l;