From 6b63520ed14b17bbe9c2103debbd2152dde1fba3 Mon Sep 17 00:00:00 2001 From: Guixiong Wei Date: Tue, 2 Jun 2026 10:07:52 +0800 Subject: [PATCH] platform/x86/intel-uncore-freq: Fix current_freq_khz after CPU hotplug MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When the last CPU of a legacy uncore die goes offline, uncore_freq_remove_die_entry() clears control_cpu. During CPU hotplug re-add, uncore_freq_add_entry() still populates sysfs attributes before assigning the new control CPU. As a result, the current frequency read returns -ENXIO and current_freq_khz is omitted from the recreated sysfs group. Assign control_cpu before the initial read paths and before create_attr_group() so sysfs recreation uses the new online CPU. If sysfs creation fails, restore control_cpu to -1 to keep the error path state consistent. Fixes: 4d73c6772ab7 ("platform/x86: intel-uncore-freq: Conditionally create attribute for read frequency") Cc: stable@vger.kernel.org Signed-off-by: Guixiong Wei Acked-by: Srinivas Pandruvada Link: https://patch.msgid.link/20260602020752.3126-1-weiguixiong@bytedance.com Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen --- .../x86/intel/uncore-frequency/uncore-frequency-common.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-common.c b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-common.c index 3b554418a7a3..4bcafedf68ef 100644 --- a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-common.c +++ b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-common.c @@ -285,15 +285,20 @@ int uncore_freq_add_entry(struct uncore_data *data, int cpu) data->package_id, data->die_id); } + /* + * Set the control CPU before any read path so entry recreation after CPU + * hotplug can populate read-only attributes from the new online CPU. + */ + data->control_cpu = cpu; uncore_read(data, &data->initial_min_freq_khz, UNCORE_INDEX_MIN_FREQ); uncore_read(data, &data->initial_max_freq_khz, UNCORE_INDEX_MAX_FREQ); ret = create_attr_group(data, data->name); if (ret) { + data->control_cpu = -1; if (data->domain_id != UNCORE_DOMAIN_ID_INVALID) ida_free(&intel_uncore_ida, data->seqnum_id); } else { - data->control_cpu = cpu; data->valid = true; }