From 57476909c3000a04e84a1d6018d63ba1b2aa20ab Mon Sep 17 00:00:00 2001 From: Marco Scardovi Date: Tue, 9 Jun 2026 09:29:03 +0200 Subject: [PATCH] cpufreq/amd-pstate: Fix EPP return type and handle errors during initialization Currently, the EPP getter helper functions (msr_get_epp, shmem_get_epp, and the static call wrapper amd_pstate_get_epp) return u8 or s16. This makes it difficult to correctly propagate negative error values returned by the underlying MSR read or CPPC helpers (such as rdmsrq_on_cpu or cppc_get_epp_perf). Modify the return type of these functions to int, allowing them to return negative error codes properly. Additionally, in amd_pstate_epp_cpu_init(), fetch the firmware-programmed default EPP value and validate it before assigning it to the EPP variables. If amd_pstate_get_epp() returns an error code, propagate the error and abort the CPU initialization to prevent subsequent configuration failures. Fixes: 555bbe67a622 ("cpufreq/amd-pstate: Convert all perf values to u8") Assisted-by: Antigravity:gemini-3.5-flash Reviewed-by: K Prateek Nayak Tested-by: K Prateek Nayak Signed-off-by: Marco Scardovi Reviewed-by: K Prateek Nayak Link: https://lore.kernel.org/r/20260609073042.81275-2-scardracs@disroot.org Signed-off-by: Mario Limonciello --- drivers/cpufreq/amd-pstate.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 3a6b4b224a66..477c17398fc2 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -199,7 +199,7 @@ static inline int get_mode_idx_from_str(const char *str, size_t size) static DEFINE_MUTEX(amd_pstate_driver_lock); -static u8 msr_get_epp(struct amd_cpudata *cpudata) +static int msr_get_epp(struct amd_cpudata *cpudata) { u64 value; int ret; @@ -215,12 +215,12 @@ static u8 msr_get_epp(struct amd_cpudata *cpudata) DEFINE_STATIC_CALL(amd_pstate_get_epp, msr_get_epp); -static inline s16 amd_pstate_get_epp(struct amd_cpudata *cpudata) +static inline int amd_pstate_get_epp(struct amd_cpudata *cpudata) { return static_call(amd_pstate_get_epp)(cpudata); } -static u8 shmem_get_epp(struct amd_cpudata *cpudata) +static int shmem_get_epp(struct amd_cpudata *cpudata) { u64 epp; int ret; @@ -1876,6 +1876,7 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) struct amd_cpudata *cpudata; union perf_cached perf; struct device *dev; + int default_epp; int ret; /* @@ -1924,6 +1925,13 @@ 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 */ + default_epp = amd_pstate_get_epp(cpudata); + if (default_epp < 0) { + ret = default_epp; + goto free_cpudata1; + } + /* * Set the policy to provide a valid fallback value in case * the default cpufreq governor is neither powersave nor performance. @@ -1931,7 +1939,7 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) if (amd_pstate_acpi_pm_profile_server() || amd_pstate_acpi_pm_profile_undefined()) { policy->policy = CPUFREQ_POLICY_PERFORMANCE; - cpudata->epp_default_ac = cpudata->epp_default_dc = amd_pstate_get_epp(cpudata); + cpudata->epp_default_ac = cpudata->epp_default_dc = default_epp; cpudata->current_profile = PLATFORM_PROFILE_PERFORMANCE; } else { policy->policy = CPUFREQ_POLICY_POWERSAVE;