Some Intel Tiger Lake-UP3/UP4 CPU models (TGL, family 6, model 140, stepping 1) have reports of system hangs when a microcode update, that is included since microcode-20201110 update, is applied[1]. In order to address this, microcode update has been disabled by default on these systems. [1] https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files/issues/44 For the reference, SHA1 checksums of 06-8c-01 microcode files containing microcode revisions in question are listed below: * 06-8c-01, revision 0x68: 2204a6dee1688980cd228268fdf4b6ed5904fe04 * 06-8c-01, revision 0x88: 61b6590feb2769046d5b0c394179beaf2df51290 Please contact your system vendor for a BIOS/firmware update that contains the latest microcode version. The information regarding enforcing microcode update is provided below. To enforce usage of the latest 06-8c-01 microcode revision for a specific kernel version, please create a file "force-intel-06-8c-01" inside /lib/firmware/ directory, run "/usr/libexec/microcode_ctl/update_ucode" to add it to firmware directory where microcode will be available for late microcode update, and run "dracut -f --kver ", so initramfs for this kernel version is regenerated and the microcode can be loaded early, for example: touch /lib/firmware/3.10.0-862.9.1/force-intel-06-8c-01 /usr/libexec/microcode_ctl/update_ucode dracut -f --kver 3.10.0-862.9.1 After that, it is possible to perform a late microcode update by executing "/usr/libexec/microcode_ctl/reload_microcode" or by writing value "1" to "/sys/devices/system/cpu/microcode/reload" directly. To enforce addition of this microcode for all kernels, please create file "/etc/microcode_ctl/ucode_with_caveats/force-intel-06-8c-01", run "/usr/libexec/microcode_ctl/update_ucode" for enabling late microcode updates, and "dracut -f --regenerate-all" for enabling early microcode updates: mkdir -p /etc/microcode_ctl/ucode_with_caveats touch /etc/microcode_ctl/ucode_with_caveats/force-intel-06-8c-01 /usr/libexec/microcode_ctl/update_ucode dracut -f --regenerate-all Please refer to /usr/share/doc/microcode_ctl/README.caveats for additional information.