From d0f4c1c8cbffcfd5db683bd3f54396bfec12e9f5 Mon Sep 17 00:00:00 2001 From: Marco Scardovi Date: Tue, 9 Jun 2026 09:29:05 +0200 Subject: cpufreq/amd-pstate: Cache the firmware programmed EPP value At CPU EPP initialization, the private cpudata structure is allocated via kzalloc, which means cpudata->cppc_req_cached is initialized to 0. This makes the default cached EPP value 0 (AMD_CPPC_EPP_PERFORMANCE). When initializing a system that defaults to performance EPP, the driver attempts to configure the EPP via amd_pstate_set_epp(). Because the requested EPP (0) matches the uninitialized cached value (0), the cache guard check triggers, and the driver skips writing to the hardware. Cache the firmware-programmed default EPP value in cppc_req_cached during CPU EPP initialization. This saves on an unnecessary reprogramming later when the EPP is first set. Assisted-by: Antigravity:gemini-3.5-flash Reviewed-by: K Prateek Nayak Tested-by: K Prateek Nayak Signed-off-by: Marco Scardovi Link: https://lore.kernel.org/r/20260609073042.81275-4-scardracs@disroot.org Signed-off-by: Mario Limonciello --- drivers/cpufreq/amd-pstate.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 3c2995686a50..19d9e574ce5a 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -1922,12 +1922,13 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) policy->boost_supported = READ_ONCE(cpudata->boost_supported); - /* Fetch the firmware programmed default EPP value */ + /* Cache the firmware programmed EPP */ default_epp = amd_pstate_get_epp(cpudata); if (default_epp < 0) { ret = default_epp; goto free_cpudata1; } + FIELD_MODIFY(AMD_CPPC_EPP_PERF_MASK, &cpudata->cppc_req_cached, default_epp); /* * Set the policy to provide a valid fallback value in case -- cgit v1.2.3