]> git.ipfire.org Git - thirdparty/kernel/stable.git/commit
ACPI: CPPC: Fix bit_offset shift in MASK_VAL() macro
authorJarred White <jarredwhite@linux.microsoft.com>
Tue, 9 Apr 2024 05:23:09 +0000 (22:23 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 2 May 2024 14:35:30 +0000 (16:35 +0200)
commit5cfdf783323fa4f3990314509317d880982c5305
treee596a717b12e233b5529fef62a47eb67e926f008
parent6cb6b12b78dcd8867a3fdbb1b6d0ed1df2b208d1
ACPI: CPPC: Fix bit_offset shift in MASK_VAL() macro

commit 05d92ee782eeb7b939bdd0189e6efcab9195bf95 upstream.

Commit 2f4a4d63a193 ("ACPI: CPPC: Use access_width over bit_width for
system memory accesses") neglected to properly wrap the bit_offset shift
when it comes to applying the mask. This may cause incorrect values to be
read and may cause the cpufreq module not be loaded.

[   11.059751] cpu_capacity: CPU0 missing/invalid highest performance.
[   11.066005] cpu_capacity: partial information: fallback to 1024 for all CPUs

Also, corrected the bitmask generation in GENMASK (extra bit being added).

Fixes: 2f4a4d63a193 ("ACPI: CPPC: Use access_width over bit_width for system memory accesses")
Signed-off-by: Jarred White <jarredwhite@linux.microsoft.com>
Cc: 5.15+ <stable@vger.kernel.org> # 5.15+
Reviewed-by: Vanshidhar Konda <vanshikonda@os.amperecomputing.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/acpi/cppc_acpi.c