From: David Brownell For the "cmos" RTC, have /proc/driver/rtc say whether HPET based IRQ emulation is in effect. Given the problems we've had with this particular hardware maldesign (and the fact that most BIOS code seems not to provide the IRQ routing needed to use the saner HPET modes), this should help troubleshooting. Signed-off-by: David Brownell Cc: Alessandro Zummo Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- drivers/rtc/rtc-cmos.c | 2 ++ 1 file changed, 2 insertions(+) diff -puN drivers/rtc/rtc-cmos.c~rtc-cmos-display-hpet-emulation-mode drivers/rtc/rtc-cmos.c --- a/drivers/rtc/rtc-cmos.c~rtc-cmos-display-hpet-emulation-mode +++ a/drivers/rtc/rtc-cmos.c @@ -388,6 +388,7 @@ static int cmos_procfs(struct device *de return seq_printf(seq, "periodic_IRQ\t: %s\n" "update_IRQ\t: %s\n" + "HPET_emulated\t: %s\n" // "square_wave\t: %s\n" // "BCD\t\t: %s\n" "DST_enable\t: %s\n" @@ -395,6 +396,7 @@ static int cmos_procfs(struct device *de "batt_status\t: %s\n", (rtc_control & RTC_PIE) ? "yes" : "no", (rtc_control & RTC_UIE) ? "yes" : "no", + is_hpet_enabled() ? "yes" : "no", // (rtc_control & RTC_SQWE) ? "yes" : "no", // (rtc_control & RTC_DM_BINARY) ? "no" : "yes", (rtc_control & RTC_DST_EN) ? "yes" : "no", _