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| author | Mario Limonciello <mario.limonciello@amd.com> | 2022-07-05 20:29:14 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-07-05 20:36:11 +0200 |
| commit | 7feec7430edddb87c24b0a86b08a03d0b496a755 (patch) | |
| tree | 52f12c34344cda0070472741c38b7e830a1e7bb9 /drivers/acpi/cppc_acpi.c | |
| parent | Linux 5.19-rc5 (diff) | |
| download | linux-7feec7430edddb87c24b0a86b08a03d0b496a755.tar.xz linux-7feec7430edddb87c24b0a86b08a03d0b496a755.zip | |
ACPI: CPPC: Only probe for _CPC if CPPC v2 is acked
Previously the kernel used to ignore whether the firmware masked CPPC
or CPPCv2 and would just pretend that it worked.
When support for the USB4 bit in _OSC was introduced from commit
9e1f561afb ("ACPI: Execute platform _OSC also with query bit clear")
the kernel began to look at the return when the query bit was clear.
This caused regressions that were misdiagnosed and attempted to be solved
as part of commit 2ca8e6285250 ("Revert "ACPI: Pass the same capabilities
to the _OSC regardless of the query flag""). This caused a different
regression where non-Intel systems weren't able to negotiate _OSC
properly.
This was reverted in commit 2ca8e6285250 ("Revert "ACPI: Pass the same
capabilities to the _OSC regardless of the query flag"") and attempted to
be fixed by commit c42fa24b4475 ("ACPI: bus: Avoid using CPPC if not
supported by firmware") but the regression still returned.
These systems with the regression only load support for CPPC from an SSDT
dynamically when _OSC reports CPPC v2. Avoid the problem by not letting
CPPC satisfy the requirement in `acpi_cppc_processor_probe`.
Reported-by: CUI Hao <cuihao.leo@gmail.com>
Reported-by: maxim.novozhilov@gmail.com
Reported-by: lethe.tree@protonmail.com
Reported-by: garystephenwright@gmail.com
Reported-by: galaxyking0419@gmail.com
Fixes: c42fa24b4475 ("ACPI: bus: Avoid using CPPC if not supported by firmware")
Fixes: 2ca8e6285250 ("Revert "ACPI Pass the same capabilities to the _OSC regardless of the query flag"")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=213023
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2075387
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: CUI Hao <cuihao.leo@gmail.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/cppc_acpi.c')
| -rw-r--r-- | drivers/acpi/cppc_acpi.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 903528f7e187..d64facbda0fb 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -684,8 +684,10 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) acpi_status status; int ret = -ENODATA; - if (osc_sb_cppc_not_supported) + if (!osc_sb_cppc2_support_acked) { + pr_debug("CPPC v2 _OSC not acked\n"); return -ENODEV; + } /* Parse the ACPI _CPC table for this CPU. */ status = acpi_evaluate_object_typed(handle, "_CPC", NULL, &output, |