diff options
Diffstat (limited to 'drivers/acpi/processor_idle.c')
| -rw-r--r-- | drivers/acpi/processor_idle.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 89d3fd4c3cd2..5551bfbc47aa 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -365,7 +365,9 @@ static void acpi_processor_idle(void) t1 = inl(acpi_fadt.xpm_tmr_blk.address); /* Invoke C2 */ inb(cx->address); - /* Dummy op - must do something useless after P_LVL2 read */ + /* Dummy wait op - must do something useless after P_LVL2 read + because chipsets cannot guarantee that STPCLK# signal + gets asserted in time to freeze execution properly. */ t2 = inl(acpi_fadt.xpm_tmr_blk.address); /* Get end time (ticks) */ t2 = inl(acpi_fadt.xpm_tmr_blk.address); @@ -403,7 +405,7 @@ static void acpi_processor_idle(void) t1 = inl(acpi_fadt.xpm_tmr_blk.address); /* Invoke C3 */ inb(cx->address); - /* Dummy op - must do something useless after P_LVL3 read */ + /* Dummy wait op (see above) */ t2 = inl(acpi_fadt.xpm_tmr_blk.address); /* Get end time (ticks) */ t2 = inl(acpi_fadt.xpm_tmr_blk.address); |