From f64fb7c5338fde361fdaef01b98697a52ee8467b Mon Sep 17 00:00:00 2001 From: Srinivas Pandruvada Date: Sun, 27 Jul 2025 14:05:13 -0700 Subject: platform/x86/intel-uncore-freq: Check write blocked for ELC MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add the missing write_blocked check for updating sysfs related to uncore efficiency latency control (ELC). If write operation is blocked return error. Fixes: bb516dc79c4a ("platform/x86/intel-uncore-freq: Add support for efficiency latency control") Signed-off-by: Srinivas Pandruvada Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250727210513.2898630-1-srinivas.pandruvada@linux.intel.com Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen --- .../x86/intel/uncore-frequency/uncore-frequency-tpmi.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-tpmi.c +++ b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-tpmi.c @@ -191,9 +191,14 @@ static int uncore_read_control_freq(stru static int write_eff_lat_ctrl(struct uncore_data *data, unsigned int val, enum uncore_index index) { struct tpmi_uncore_cluster_info *cluster_info; + struct tpmi_uncore_struct *uncore_root; u64 control; cluster_info = container_of(data, struct tpmi_uncore_cluster_info, uncore_data); + uncore_root = cluster_info->uncore_root; + + if (uncore_root->write_blocked) + return -EPERM; if (cluster_info->root_domain) return -ENODATA;