linux-stable.git/drivers/idle, branch master

Merge branch 'intel-idle-lpi'

2026-08-07T19:22:50+00:00

Merge an ACPI processor driver update related to ACPI _LPI support and
the introduction of ACPI _LPI suppor to intel_idle based on that update
for 7.3-rc1.

* intel-idle-lpi:
  intel_idle: Update documentation after adding ACPI _LPI support
  intel_idle: Add ACPI _LPI support
  intel_idle: Prepare for adding ACPI _LPI support
  ACPI: processor: idle: Add switch for strict _LPI processing
  ACPI: processor: idle: Relocate acpi_processor_extract_lpi_info()
  ACPI: processor: idle: Introduce acpi_processor_extract_lpi_info()
  ACPI: processor: idle: Introduce too_many_states() for _LPI
  ACPI: processor: idle: Rework flatten_lpi_states()
  ACPI: processor: idle: Rearrange loop in acpi_processor_get_lpi_info()
  ACPI: processor: idle: Drop redundant _LPI presence checks
  ACPI: processor: idle: Rework first-level _LPI states processing
  ACPI: processor: idle: Rearrange acpi_processor_get_lpi_info()
  ACPI: processor: idle: Introduce lpi_state_debug()
  ACPI: processor: idle: Split acpi_processor_evaluate_lpi()
  ACPI: processor: idle: Rearrange acpi_processor_evaluate_lpi()
  ACPI: processor: idle: Unify debug in acpi_processor_evaluate_lpi()
  ACPI: processor: idle: Ignore _LPI states with SYSTEMIO entry method
  ACPI: processor: idle: Expand _LPI package sanity checks

intel_idle: Avoid using deep idle states during initialization

2026-08-05T12:26:30+00:00

Commit c0f691388992 ("intel_idle: Use subsys_initcall_sync() for
initialization") effectively made intel_idle initialize earlier which
turns out to interfere with USB EHCI probing on some platforms [1].
Investigation led to the conclusion that this was related to allowing
package idle states to be used earlier than before.

Work around that issue by making intel_idle set a CPU latency QoS
request to prevent package idle states from being used on all platforms
supported by it for the duration of the device_initcall() initialization
phase.

Fixes: c0f691388992 ("intel_idle: Use subsys_initcall_sync() for initialization")
Reported-by: Julian Silver 
Tested-by: Julian Silver 
Closes: https://lore.kernel.org/linux-acpi/3353bdf3-4f33-44b1-809b-b0378bee5816@gmail.com/
Signed-off-by: Rafael J. Wysocki 
Link: https://patch.msgid.link/5120454.31r3eYUQgx@rafael.j.wysocki

intel_idle: Add ACPI _LPI support

2026-07-17T09:10:10+00:00

Allow intel_idle to use idle states information coming from ACPI _LPI
objects by making it call acpi_processor_extract_lpi_info() and, if
that is successful, using the list of idle states produced by that
function instead of the one coming from acpi_processor_evaluate_cst().

Signed-off-by: Rafael J. Wysocki 
Link: https://patch.msgid.link/2280567.Icojqenx9y@rafael.j.wysocki

intel_idle: Prepare for adding ACPI _LPI support

2026-07-17T09:10:09+00:00

In preparation for adding ACPI _LPI support to intel_idle, move some
code used for processing ACPI idle states information coming from
_CST objects to separate functions because that code will be also
used for processing idle states information coming from _LPI.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki 
Link: https://patch.msgid.link/1932965.atdPhlSkOF@rafael.j.wysocki

Merge tag 'x86-msr-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

2026-06-15T09:38:14+00:00

Pull x86/msr updates from Ingo Molnar:

 - Large series to reorganize the rdmsr/wrmsr APIs to remove
   32-bit variants and convert to 64-bit variants (Juergen Gross)

 - Fix W=1 warning (HyeongJun An)

* tag 'x86-msr-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
  x86/msr: Remove wrmsrl()
  x86/msr: Switch wrmsrl() users to wrmsrq()
  x86/msr: Remove rdmsrl()
  x86/msr: Switch rdmsrl() users to rdmsrq()
  x86/msr: Remove wrmsr_safe_on_cpu()
  x86/msr: Switch wrmsr_safe_on_cpu() users to wrmsrq_safe_on_cpu()
  x86/msr: Remove rdmsr_safe_on_cpu()
  x86/msr: Switch rdmsr_safe_on_cpu() users to rdmsrq_safe_on_cpu()
  x86/msr: Don't use rdmsr_safe_on_cpu() in rdmsrq_safe_on_cpu()
  x86/msr: Remove wrmsr_on_cpu()
  x86/msr: Switch wrmsr_on_cpu() users to wrmsrq_on_cpu()
  x86/msr: Remove rdmsr_on_cpu()
  x86/msr: Switch rdmsr_on_cpu() users to rdmsrq_on_cpu()
  x86/msr: Remove rdmsrl_on_cpu()
  x86/msr: Switch rdmsrl_on_cpu() user to rdmsrq_on_cpu()
  x86/process: Convert rdmsr() to rdmsrq() in arch_post_acpi_subsys_init() to address W=1 warning

x86/msr: Switch wrmsrl() users to wrmsrq()

2026-06-08T11:16:35+00:00

wrmsrl() is a deprecated synonym for wrmsrq(). Switch its users to
wrmsrq().

Signed-off-by: Juergen Gross 
Signed-off-by: Ingo Molnar 
Cc: Sean Christopherson 
Cc: Paolo Bonzini 
Cc: "K. Y. Srinivasan" 
Cc: Haiyang Zhang 
Cc: Wei Liu 
Cc: Dexuan Cui 
Cc: Long Li 
Cc: "Rafael J. Wysocki" 
Cc: Artem Bityutskiy 
Link: https://patch.msgid.link/20260608082809.3492719-4-jgross@suse.com

x86/msr: Switch rdmsrl() users to rdmsrq()

2026-06-08T11:16:34+00:00

rdmsrl() is a deprecated synonym for rdmsrq(). Switch its users to
rdmsrq().

Signed-off-by: Juergen Gross 
Signed-off-by: Ingo Molnar 
Cc: "K. Y. Srinivasan" 
Cc: Haiyang Zhang 
Cc: Wei Liu 
Cc: Dexuan Cui 
Cc: Long Li 
Cc: "Rafael J. Wysocki" 
Cc: Artem Bityutskiy 
Link: https://patch.msgid.link/20260608082809.3492719-2-jgross@suse.com

intel_idle: Drop C-states redundant when PC6 is disabled

2026-05-20T20:36:02+00:00

On modern Xeon platforms, such as Granite Rapids, Sierra Forest, and
Clearwater Forest, there are two flavors of requestable C6 states: C6
and C6P. C6 allows only core C6 (CC6), while C6P allows both CC6 and
package C6 (PC6). PC6 saves more power but also has a higher exit
latency, so many users disable it in BIOS.

When PC6 is disabled, C6P becomes identical to C6 — the CPU treats C6P
requests as C6 requests. Exposing both C6 and C6P to user space in this
situation is confusing: two states with the same name look different but
behave the same. It also adds unnecessary overhead to the cpuidle
subsystem, which is a fast path: the governor evaluates every registered
state on idle entry.

Drop C-states that are redundant when PC6 is disabled by marking them
with CPUIDLE_FLAG_UNUSABLE, which causes cpuidle to exclude them when
registering idle states.

Signed-off-by: Artem Bityutskiy 
Link: https://patch.msgid.link/20260425072532.358365-5-dedekind1@gmail.com
Signed-off-by: Rafael J. Wysocki

intel_idle: Introduce a helper for checking PC6

2026-05-20T20:36:02+00:00

Introduce the skx_is_pc6_disabled() for checking if PC6 is disabled and
switch the following functions to use it:

 - skx_idle_state_table_update()
 - spr_idle_state_table_update()

At the same time, clean them up improving the commentary and moving it to
the function kernel-doc.

Purely a clean up, no functional changes intended.

Reviewed-by: Andy Shevchenko 
Signed-off-by: Artem Bityutskiy 
Link: https://patch.msgid.link/20260425072532.358365-4-dedekind1@gmail.com
Signed-off-by: Rafael J. Wysocki

intel_idle: Add constants for MSR_PKG_CST_CONFIG_CONTROL

2026-05-20T20:36:02+00:00

Add two constants for the package C-state limit fields in
MSR_PKG_CST_CONFIG_CONTROL.

The SKX_ prefix stands for "Skylake Xeon" and makes it explicit that
the mask is CPU model-specific. The same values have applied to all
Xeon platforms starting from SKX.

Reviewed-by: Andy Shevchenko 
Signed-off-by: Artem Bityutskiy 
Link: https://patch.msgid.link/20260425072532.358365-2-dedekind1@gmail.com
Signed-off-by: Rafael J. Wysocki