rtc: fix reported IRQ rate for when HPET is enabled

commit 61ca9daa2ca3022dc9cb22bd98e69c1b61e412ad upstream

The IRQ rate reported back by the RTC is incorrect when HPET is enabled.

Newer hardware that has HPET to emulate the legacy RTC device gets this value
wrong since after it sets the rate, it returns before setting the variable
used to report the IRQ rate back to users of the device -- so the set rate and
the reported rate get out of sync.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Brownell <david-b@pacbell.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/char/rtc.c b/drivers/char/rtc.c
index 5c3142b6f1fcdf102a92b79dec3b9d000b4d4a3b..81ecec0c65b59dd46a3db97c607476ddaf907691 100644 (file)
--- a/drivers/char/rtc.c
+++ b/drivers/char/rtc.c
@@ -677,12 +677,13 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
                if (arg != (1<<tmp))
                        return -EINVAL;
 
+               rtc_freq = arg;
+
                spin_lock_irqsave(&rtc_lock, flags);
                if (hpet_set_periodic_freq(arg)) {
                        spin_unlock_irqrestore(&rtc_lock, flags);
                        return 0;
                }
-               rtc_freq = arg;
 
                val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0;
                val |= (16 - tmp);