> -----Original Message----- > From: platform-driver-x86-owner@xxxxxxxxxxxxxxx [mailto:platform-driver-x86- > owner@xxxxxxxxxxxxxxx] On Behalf Of Rafael J. Wysocki > Sent: Wednesday, January 10, 2018 6:26 AM > To: Linux ACPI <linux-acpi@xxxxxxxxxxxxxxx> > Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>; Darren Hart > <dvhart@xxxxxxxxxxxxx>; LKML <linux-kernel@xxxxxxxxxxxxxxx>; Linux PM <linux- > pm@xxxxxxxxxxxxxxx>; Platform Driver <platform-driver-x86@xxxxxxxxxxxxxxx>; > Valentin Manea <valy@xxxxxx> > Subject: [PATCH 1/2] ACPI / PM: Use Low Power S0 Idle on more systems > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > Some systems don't support the ACPI_LPS0_ENTRY and ACPI_LPS0_EXIT > functions in their Low Power S0 Idle _DSM, but still expect EC > events to be processed in the suspend-to-idle state for power button > wakeup (among other things) to work. Surface Pro3 turns out to be > one of them. > > Fortunately, it still provides Low Power S0 Idle _DSM with the screen > on/off functions supported, so modify the ACPI suspend-to-idle to use > the Low Power S0 Idle code path for all systems supporting the > ACPI_LPS0_ENTRY and ACPI_LPS0_EXIT or the ACPI_LPS0_SCREEN_OFF and > ACPI_LPS0_SCREEN_ON functions in their Low Power S0 Idle _DSM. > > Potentially, that will cause more systems to use suspend-to-idle by > default, so some future corrections may be necessary if it leads > to issues, but let it remain more straightforward for now. > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=198389 > Reported-by: Valentin Manea <valy@xxxxxx> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > --- > drivers/acpi/sleep.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > Index: linux-pm/drivers/acpi/sleep.c > =================================================================== > --- linux-pm.orig/drivers/acpi/sleep.c > +++ linux-pm/drivers/acpi/sleep.c > @@ -707,7 +707,8 @@ static const struct acpi_device_id lps0_ > #define ACPI_LPS0_ENTRY 5 > #define ACPI_LPS0_EXIT 6 > > -#define ACPI_S2IDLE_FUNC_MASK ((1 << ACPI_LPS0_ENTRY) | (1 << > ACPI_LPS0_EXIT)) > +#define ACPI_LPS0_SCREEN_MASK ((1 << ACPI_LPS0_SCREEN_OFF) | (1 << > ACPI_LPS0_SCREEN_ON)) > +#define ACPI_LPS0_S2I_MASK ((1 << ACPI_LPS0_ENTRY) | (1 << ACPI_LPS0_EXIT)) > > static acpi_handle lps0_device_handle; > static guid_t lps0_dsm_guid; > @@ -910,7 +911,8 @@ static int lps0_device_attach(struct acp > if (out_obj && out_obj->type == ACPI_TYPE_BUFFER) { > char bitmask = *(char *)out_obj->buffer.pointer; > > - if ((bitmask & ACPI_S2IDLE_FUNC_MASK) == > ACPI_S2IDLE_FUNC_MASK) { > + if ((bitmask & ACPI_LPS0_S2I_MASK) == ACPI_LPS0_S2I_MASK || > + (bitmask & ACPI_LPS0_SCREEN_MASK) == > ACPI_LPS0_SCREEN_MASK) { > lps0_dsm_func_mask = bitmask; > lps0_device_handle = adev->handle; > /* In making this change I believe you'll need to cache the values that you found from the function mask to test them later too. Here: https://github.com/torvalds/linux/blob/master/drivers/acpi/sleep.c#L943 This is because later on both ACPI_LPS0_SCREEN_OFF and ACPI_LPS0_ENTRY are called whether or not they both exist. Fortunately looking at the DSDT in the attached bug nothing happens if calling the undefined Arg2 == 0x05/Arg2 == 0x06 but that might not always be the case. -- 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
