linux.git/drivers/acpi/sleep.c, branch v5.6

ACPI: PM: s2idle: Check fixed wakeup events in acpi_s2idle_wake()

2020-02-21T18:01:25+00:00

Commit fdde0ff8590b ("ACPI: PM: s2idle: Prevent spurious SCIs from
waking up the system") overlooked the fact that fixed events can wake
up the system too and broke RTC wakeup from suspend-to-idle as a
result.

Fix this issue by checking the fixed events in acpi_s2idle_wake() in
addition to checking wakeup GPEs and break out of the suspend-to-idle
loop if the status bits of any enabled fixed events are set then.

Fixes: fdde0ff8590b ("ACPI: PM: s2idle: Prevent spurious SCIs from waking up the system")
Reported-and-tested-by: Chris Wilson 
Cc: 5.4+  # 5.4+
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Linus Torvalds

ACPI: PM: s2idle: Prevent spurious SCIs from waking up the system

2020-02-11T22:26:15+00:00

If the platform triggers a spurious SCI even though the status bit
is not set for any GPE when the system is suspended to idle, it will
be treated as a genuine wakeup, so avoid that by checking if any GPEs
are active at all before returning 'true' from acpi_s2idle_wake().

Link: https://bugzilla.kernel.org/show_bug.cgi?id=206413
Fixes: 56b991849009 ("PM: sleep: Simplify suspend-to-idle control flow")
Reported-by: Tsuchiya Yuto 
Cc: 5.4+  # 5.4+
Signed-off-by: Rafael J. Wysocki

ACPI: PM: s2idle: Avoid possible race related to the EC GPE

2020-02-11T09:11:02+00:00

It is theoretically possible for the ACPI EC GPE to be set after the
s2idle_ops->wake() called from s2idle_loop() has returned and before
the subsequent pm_wakeup_pending() check is carried out.  If that
happens, the resulting wakeup event will cause the system to resume
even though it may be a spurious one.

To avoid that race, first make the ->wake() callback in struct
platform_s2idle_ops return a bool value indicating whether or not
to let the system resume and rearrange s2idle_loop() to use that
value instad of the direct pm_wakeup_pending() call if ->wake() is
present.

Next, rework acpi_s2idle_wake() to process EC events and check
pm_wakeup_pending() before re-arming the SCI for system wakeup
to prevent it from triggering prematurely and add comments to
that function to explain the rationale for the new code flow.

Fixes: 56b991849009 ("PM: sleep: Simplify suspend-to-idle control flow")
Cc: 5.4+  # 5.4+
Signed-off-by: Rafael J. Wysocki

ACPI/sleep: Convert acpi_wakeup_address into a function

2019-12-10T09:15:48+00:00

Convert acpi_wakeup_address from a raw variable into a function so that
x86 can wrap its dereference of the real mode boot header in a function
instead of broadcasting it to the world via a #define.  This sets the
stage for a future patch to move x86's definition of the new function,
acpi_get_wakeup_address(), out of asm/acpi.h and thus break acpi.h's
dependency on asm/realmode.h.

No functional change intended.

Signed-off-by: Sean Christopherson 
Link: https://lkml.kernel.org/r/20191126165417.22423-12-sean.j.christopherson@intel.com
Signed-off-by: Ingo Molnar

ACPI: PM: s2idle: Rework ACPI events synchronization

2019-12-02T08:23:23+00:00

Note that the EC GPE processing need not be synchronized in
acpi_s2idle_wake() after invoking acpi_ec_dispatch_gpe(), because
that function checks the GPE status and dispatches its handler if
need be and the SCI action handler is not going to run anyway at
that point.

Moreover, it is better to drain all of the pending ACPI events
before restoring the working-state configuration of GPEs in
acpi_s2idle_restore(), because those events are likely to be related
to system wakeup, in which case they will not be relevant going
forward.

Rework the code to take these observations into account.

Tested-by: Kenneth R. Crudup 
Signed-off-by: Rafael J. Wysocki

ACPI: PM: Drop Dell XPS13 9360 from LPS0 Idle _DSM blacklist

2019-10-10T08:50:20+00:00

This reverts part of commit 71630b7a832f ("ACPI / PM: Blacklist Low
Power S0 Idle _DSM for Dell XPS13 9360") to remove the S0ix blacklist
for the XPS 9360.

The problems with this system occurred in one possible NVME SSD when
putting system into s0ix.  As the NVME sleep behavior has been adjusted
in commit d916b1be94b6 ("nvme-pci: use host managed power state for
suspend") this is expected to be now resolved.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=196907
Signed-off-by: Mario Limonciello 
Tested-by: Paul Menzel 
Signed-off-by: Rafael J. Wysocki

ACPI: PM: s2idle: Always set up EC GPE for system wakeup

2019-08-21T21:56:05+00:00

Commit 10a08fd65ec1 ("ACPI: PM: Set up EC GPE for system wakeup from
drivers that need it") assumed that the EC GPE would only need to be
set up for system wakeup if either the intel-hid or the intel-vbtn
driver was in use, but that turns out to be incorrect.  In particular,
on ASUS Zenbook UX430UNR/i7-8550U, if the EC GPE is not enabled while
suspended, the system cannot be woken up by opening the lid or
pressing a key, and that machine doesn't use any of the drivers
mentioned above.

For this reason, always set up the EC GPE for system wakeup from
suspend-to-idle by setting and clearing its wake mask in the ACPI
suspend-to-idle callbacks.

Fixes: 10a08fd65ec1 ("ACPI: PM: Set up EC GPE for system wakeup from drivers that need it")
Reported-by: Kristian Klausen 
Tested-by: Kristian Klausen 
Acked-by: Andy Shevchenko 
Signed-off-by: Rafael J. Wysocki

ACPI: PM: s2idle: Avoid rearming SCI for wakeup unnecessarily

2019-08-21T21:55:18+00:00

It is only necessary to rearm the ACPI SCI for wakeup if
pm_system_cancel_wakeup() has been called, so invoke
rearm_wake_irq() only in that case.

Signed-off-by: Rafael J. Wysocki

ACPI: PM: s2idle: Execute LPS0 _DSM functions with suspended devices

2019-08-08T09:26:01+00:00

According to Section 3.5 of the "Intel Low Power S0 Idle" document [1],
Function 5 of the LPS0 _DSM is expected to be invoked when the system
configuration matches the criteria for entering the target low-power
state of the platform.  In particular, this means that all devices
should be suspended and in low-power states already when that function
is invoked.

This is not the case currently, however, because Function 5 of the
LPS0 _DSM is invoked by it before the "noirq" phase of device suspend,
which means that some devices may not have been put into low-power
states yet at that point.  That is a consequence of the previous
design of the suspend-to-idle flow that allowed the "noirq" phase of
device suspend and the "noirq" phase of device resume to be carried
out for multiple times while "suspended" (if any spurious wakeup
events were detected) and the point of the LPS0 _DSM Function 5
invocation was chosen so as to call it (and LPS0 _DSM Function 6
analogously) once per suspend-resume cycle (regardless of how many
times the "noirq" phases of device suspend and resume were carried
out while "suspended").

Now that the suspend-to-idle flow has been redesigned to carry out
the "noirq" phases of device suspend and resume once in each cycle,
the code can be reordered to follow the specification that it is
based on more closely.

For this purpose, add ->prepare_late and ->restore_early platform
callbacks for suspend-to-idle, to be executed, respectively, after
the "noirq" phase of suspending devices and before the "noirq"
phase of resuming them and make ACPI use them for the invocation
of LPS0 _DSM functions as appropriate.

While at it, move the LPS0 entry requirements check to be made
before invoking Functions 3 and 5 of the LPS0 _DSM (also once
per cycle) as follows from the specification [1].

Link: https://uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf # [1]
Signed-off-by: Rafael J. Wysocki 
Tested-by: Kai-Heng Feng

ACPI: PM: s2idle: Eliminate acpi_sleep_no_ec_events()

2019-08-08T09:25:37+00:00

Change acpi_ec_suspend() to use pm_suspend_no_platform() instead of
acpi_sleep_no_ec_events(), which allows the latter to be eliminated
along with the s2idle_in_progress variable which is only used by it.

Signed-off-by: Rafael J. Wysocki 
Tested-by: Kai-Heng Feng