To fix the common case where ->enable() does not set up
mult, make sure mult_orig is saved in mult on disable.
Also add comments to explain why we do this.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Cc: johnstul@us.ibm.com
Cc: lethal@linux-sh.org
Cc: akpm@linux-foundation.org
LKML-Reference: <
20090618152432.10136.9932.sendpatchset@rx1.opensource.se>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
if (cs->enable)
ret = cs->enable(cs);
if (cs->enable)
ret = cs->enable(cs);
- /* save mult_orig on enable */
+ /*
+ * The frequency may have changed while the clocksource
+ * was disabled. If so the code in ->enable() must update
+ * the mult value to reflect the new frequency. Make sure
+ * mult_orig follows this change.
+ */
cs->mult_orig = cs->mult;
return ret;
cs->mult_orig = cs->mult;
return ret;
*/
static inline void clocksource_disable(struct clocksource *cs)
{
*/
static inline void clocksource_disable(struct clocksource *cs)
{
+ /*
+ * Save mult_orig in mult so clocksource_enable() can
+ * restore the value regardless if ->enable() updates
+ * the value of mult or not.
+ */
+ cs->mult = cs->mult_orig;
+
if (cs->disable)
cs->disable(cs);
}
if (cs->disable)
cs->disable(cs);
}