diff options
| author | Christian Loehle <christian.loehle@arm.com> | 2026-07-24 11:40:42 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2026-07-27 15:18:50 +0200 |
| commit | 47d4e945dff8139050473be4ab263a32e1da910c (patch) | |
| tree | 1aafc62a2e706dbe40d0f030670524fad0d8be13 | |
| parent | 601eecdeee046d23dc313f57770ce085c8da602f (diff) | |
ACPI: CPPC: Skip writes to unsupported performance controls
MIN_PERF and MAX_PERF are optional CPPC controls. DESIRED_PERF is also
optional with CPPC2 when autonomous selection is supported.
The cppc-cpufreq target callbacks populate both limits for every request
without checking whether the controls are implemented. cppc_set_perf()
consequently passes NULL register descriptors to cpc_write(). The writes
fail width validation and their return values are ignored, so the failed
access paths are repeated on every target request. An autonomous-only
platform can take the same path for DESIRED_PERF.
Check that each performance control is supported before calling
cpc_write().
Fixes: ea3db45ae476 ("cpufreq: cppc: Update MIN_PERF/MAX_PERF in target callbacks")
Reviewed-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Christian Loehle <christian.loehle@arm.com>
Reviewed-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Link: https://patch.msgid.link/20260724104042.1481804-1-christian.loehle@arm.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/acpi/cppc_acpi.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 1d3a94100491..53d09ca98f06 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -1963,16 +1963,17 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls) cpc_desc->write_cmd_status = 0; } - cpc_write(cpu, desired_reg, perf_ctrls->desired_perf); + if (CPC_SUPPORTED(desired_reg)) + cpc_write(cpu, desired_reg, perf_ctrls->desired_perf); /* * Only write if min_perf and max_perf not zero. Some drivers pass zero * value to min and max perf, but they don't mean to set the zero value, * they just don't want to write to those registers. */ - if (perf_ctrls->min_perf) + if (perf_ctrls->min_perf && CPC_SUPPORTED(min_perf_reg)) cpc_write(cpu, min_perf_reg, perf_ctrls->min_perf); - if (perf_ctrls->max_perf) + if (perf_ctrls->max_perf && CPC_SUPPORTED(max_perf_reg)) cpc_write(cpu, max_perf_reg, perf_ctrls->max_perf); if (CPC_IN_PCC(desired_reg) || CPC_IN_PCC(min_perf_reg) || CPC_IN_PCC(max_perf_reg)) |