From: Takashi Iwai Subject: x86: workaround for mccreary HPET read problem Patch-mainline: References: bnc#433746 On mccreacy platform, the read of HPET CMP register seems not updated immediately after the write and returns the previous value instead. A workaround is to read the register twice. Signed-off-by: Takashi Iwai --- --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -278,6 +278,7 @@ static int hpet_legacy_next_event(unsign cnt += (u32) delta; hpet_writel(cnt, HPET_T0_CMP); + hpet_readl(HPET_T0_CMP); /* pre-read for bnc#433746 */ /* * We need to read back the CMP register to make sure that * what we wrote hit the chip before we compare it to the