Commit 61ca9daa authored Jul 10, 2008 by Paul Gortmaker Committed by Linus Torvalds Jul 10, 2008

rtc: fix reported IRQ rate for when HPET is enabled



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>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent ac310bb5

drivers/char/rtc.c

+2 −1

Original line number	Original line	Diff line number	Diff line
	@@ -678,12 +678,13 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
	if (arg != (1<<tmp))		if (arg != (1<<tmp))
	return -EINVAL;		return -EINVAL;

			rtc_freq = arg;

	spin_lock_irqsave(&rtc_lock, flags);		spin_lock_irqsave(&rtc_lock, flags);
	if (hpet_set_periodic_freq(arg)) {		if (hpet_set_periodic_freq(arg)) {
	spin_unlock_irqrestore(&rtc_lock, flags);		spin_unlock_irqrestore(&rtc_lock, flags);
	return 0;		return 0;
	}		}
	rtc_freq = arg;

	val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0;		val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0;
	val \|= (16 - tmp);		val \|= (16 - tmp);

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