On Wed, Jan 10, 2018 at 6:38 PM, <Mario.Limonciello@xxxxxxxx> wrote: > > >> -----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. But that's what lps0_dsm_func_mask is for if I understand you correctly. > 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. No, that's not the case. acpi_sleep_run_lps0_dsm() checks if the given function is there in the mask returned by function 0 and it doesn't evaluate the _DSM otherwise. Thanks, Rafael -- 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
