On Friday, January 10, 2014 03:52:20 PM al.stone@xxxxxxxxxx wrote: > From: Al Stone <al.stone@xxxxxxxxxx> > > ACPI ECs (Embedded Controllers) are allowed to use the ACPI global > lock in legacy mode. Since there is no global lock in hardware > reduced mode, make sure that ECs cannot inadvertently use it with > older ACPI tables that may have defined an _GLK method for the > EC device. Since an individual lock can and should be defined for > each EC, access to each EC should still be properly controlled. > > Signed-off-by: Al Stone <al.stone@xxxxxxxxxx> > --- > drivers/acpi/ec.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c > index ba5b56d..3f15110 100644 > --- a/drivers/acpi/ec.c > +++ b/drivers/acpi/ec.c > @@ -745,9 +745,17 @@ ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval) > if (ACPI_FAILURE(status)) > return status; > ec->gpe = tmp; > - /* Use the global lock for all EC transactions? */ > + /* > + * Use the global lock for all EC transactions? > + * > + * If ACPI is in hardware reduced mode, there is no global lock. > + * If a _GLK method is defined, it needs to be ignored, just > + * in case it returns "true", which could happen if the ASL is > + * written incorrectly. What is going to happen if it is defined and works correctly in turn? > + */ > tmp = 0; > - acpi_evaluate_integer(handle, "_GLK", NULL, &tmp); > + if (!acpi_gbl_reduced_hardware) > + acpi_evaluate_integer(handle, "_GLK", NULL, &tmp); > ec->global_lock = tmp; > ec->handle = handle; > return AE_CTRL_TERMINATE; > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
