This is triggered only if BIOS configures ACPI_BITREG_BUS_MASTER_RLD
aka BRLD_EN_BM to 1.
Rationale:
1. we do not support C3 on PIIX4E
2. bus master activity need not break out of C2 state
3. because of CPU_QUIRK_NO_BM_CTRL quirk we may reset bus master
status which would result in immediate break out from C2
So if you have seen
cpu0: too many short sleeps, backing off to C1
with this chipset before you may want to try cx_lowest of C2 again.
Reviewed by: rpaulo (mentor), njl
Approved by: rpaulo (mentor)
the appropriate bit in the DEVACTB register.
This change allows the C2 state on those systems to work as expected.
Reviewed by: njl
Submitted by: Andriy Gapon <avg at icyb.net.ua>
MFC after: 1 week
CPUs to make sure idle threads are evicted from the softc before returning
from acpi_cpu_shutdown(). However, this is unnecessary since stop_cpus()
handles this for itself and at this point it's possible that our IPI will be
blocked (interrupts disabled).
Thanks to: Glen Leeder <glen.leeder / nokia.com>
MFC after: 3 days
needed at least to convince the BIOS to give us access to CPU freq
control on MacBooks.
Submitted by: Rui Paulo <rpaulo / fnop.net>
Approved by: re
MFC after: 5 days
While in the suspend path, this means the idle thread will just return
immediately rather than trying to enter C1-n. This helps in the case where
the chipset is powered down before the rest of the system and reads from
the cpu sleep registers begin returning immediately, causing the logic that
catches bad C2/C3 behavior to kick in. Observed on my Panasonic Y4.
MFC after: 3 days
(j/i) was being used and it was being incremented, not decremented as before.
Factor out this code into a common function and call it from both the common
and per-CPU case.
MFC after: 1 day
modern dual-core systems as well.
- Parse the _CST packages for each cpu and track all the states individually,
on a per-cpu basis.
- Revert to generic FADT/P_BLK based Cx control if the _CST package
is not present on all cpus. In that case, the new driver will
still support per-cpu Cx state handling. The driver will determine the
highest Cx level that can be supported by all the cpus and configure the
available Cx state based on that.
- Fixed the case where multiple cpus in the system share the same
registers for Cx state handling. To do that, added a new flag
parameter to the acpi_PkgGas and acpi_bus_alloc_gas functions that
enable the caller to add the RF_SHAREABLE flag. This flag could also be
useful to other callers (acpi_throttle?) in the tree but this change is
not yet made.
- For Core Duo cpus, both cores seems to be taken out of C3 state when
any one of the cores need to transition out. This broke the short sleep
detection logic. It is disabled now if there is more than one cpu in
the system for now as it fixed it in my case. This quirk may need to
be re-enabled later differently.
- Added support to control cx_lowest on a per-cpu basis. There is still
a generic cx_lowest to enable changing cx_lowest for all cpus with a single
sysctl and for ease of use. Sample output for the new sysctl:
dev.cpu.0.cx_supported: C1/1 C2/1 C3/57
dev.cpu.0.cx_lowest: C3
dev.cpu.0.cx_usage: 0.00% 43.16% 56.83%
dev.cpu.1.cx_supported: C1/1 C2/1 C3/57
dev.cpu.1.cx_lowest: C3
dev.cpu.1.cx_usage: 0.00% 45.65% 54.34%
hw.acpi.cpu.cx_lowest: C3
This work was done by Stephane E. Potvin with some simple reworking by
myself. Thank you.
Submitted by: Stephane E. Potvin <sepotvin / videotron.ca>
MFC after: 2 weeks
immediately, back off to the next higher Cx sleep state. Some machines
with a Via chipset report a valid C3 but a register read doesn't actually
halt the CPU. This would cause the machine to appear unresponsive as it
repeatedly called cpu_idle() which immediately returned. Causing interrupts
(i.e. by pressing the power button) would cause the system to make forward
progress, showing that it wasn't actually hung.
Also, enable interrupts a little earlier. We don't need them disabled
to calculate the delta time for the read.
Reported by: silby
MFC after: 2 weeks
to see what features they may support before calling identify/probe/attach.
This is necessary because the ACPI 3.0 spec requires driver support be
advertised before running any methods. For now, the flags are as specified
in for the _PDC and _OSC methods but we can support private flags as needed.
Add an implementation of this for acpi_cpu. It checks all its children
(notably cpufreq drivers) and calls the _PDC method to report the results.
doing it in the cpu driver. The previous code was incorrect anyway since
this value controls Px states, not throttling as the comment said. Since
we didn't support Px states before, there was no impact. Also, note that
we delay the write to SMI_CMD until after booting is complete since it
sometimes triggers a change in the frequency and we want to have all
drivers ready to detect/handle this.
devclass. As pointed out by dfr@, devclasses don't have to share the same
linkage if multiple drivers have the same name. Newbus should match the
devclasses based on name and allocate non-conflicting unit numbers.
after boot so that PCI is initialized and we can probe for the problem
chipsets. Note that while probed but unusable states are disabled, they
aren't freed yet. In the future, it may make sense to detach them.
Tested by: Adam K Kirchoff <adamk at voicenet com>
MFC after: 2 days
* Fix a bug where caches were flushed on non-C3 transitions.
* Be sure a working flush cache instruction is present before using it.
* Disable C3 completely if it isn't present.
after. Unify the paths for all Cx states. Remove cpu_idle_busy and
instead do the little profiling we need before re-enabling interrupts.
Use 1 quantum as estimate for C1 sleep duration since the timer interrupt
is the main reason we wake.
While here, change the cx_history sysctl to cx_usage and report statistics
for which idle states were used in terms of percent. This seems more
intuitive than counters. Remove the cx_stats structure since it's no
longer used. Update the man page.
Change various types which do not need explicit size.
devices it cannot attach to. This gets rid of extraneous but harmless
device_probe_and_attach() errors. While I'm here, make the device
description more useful. The !acpi case for cpu is handled by legacy0.
globally available. acpi_TimerDelta() subtracts two readings from the
ACPI PM timer and returns the difference. It properly distinguishes between
24-bit and 32-bit timers and handles wraparound.
even though the spec mandates this. Some have a value of 5 to indicate
throttling + C2 and some have 7 to indicate an extra C3 state. Support
throttling if the value is >= 4, C2 for >= 5, and C3 for >= 6.
throttling values being available regardless of the CPU's capabilities.
This has been broken since rev 1.1. Also clarify a comment.
Submitted by: Taku YAMAMATO <taku@cent.saitama-u.ac.jp>
