It looks like this is the Intel graphics kernel driver searching for monitors.

sudo perf record -ag sleep 10
sudo perf report

# Events: 217  cycles
#
# Overhead         Command                Shared Object                                      Symbol
# ........  ..............  ...........................  ..........................................
#
    27.26%     kworker/0:2  [i915]                       [k] get_clock
               |
               --- get_clock
                  |          
                  |--99.12%-- sclhi
                  |          |          
                  |          |--86.83%-- i2c_bit_add_numbered_bus
                  |          |          i2c_bit_add_numbered_bus
                  |          |          i2c_bit_add_numbered_bus
                  |          |          i2c_bit_add_numbered_bus
                  |          |          intel_gpio_create
                  |          |          intel_gpio_create
                  |          |          i2c_transfer
                  |          |          drm_do_probe_ddc_edid
                  |          |          drm_edid_block_valid
                  |          |          intel_hdmi_detect
                  |          |          drm_target_preferred.clone.9
                  |          |          process_one_work
                  |          |          worker_thread
                  |          |          kthread
                  |          |          kernel_thread_helper
                  |          |          
                  |           --13.17%-- i2c_stop
                  |                     i2c_bit_add_numbered_bus
                  |                     |          
                  |                     |--83.32%-- i2c_bit_add_numbered_bus
                  |                     |          i2c_bit_add_numbered_bus
                  |                     |          intel_gpio_create
                  |                     |          intel_gpio_create
                  |                     |          i2c_transfer
                  |                     |          drm_do_probe_ddc_edid
                  |                     |          drm_edid_block_valid
                  |                     |          intel_hdmi_detect
                  |                     |          drm_target_preferred.clone.9
                  |                     |          process_one_work
                  |                     |          worker_thread
                  |                     |          kthread
                  |                     |          kernel_thread_helper
                  |                     |          
                  |                      --16.68%-- intel_gpio_create
                  |                                intel_gpio_create
                  |                                i2c_transfer
                  |                                drm_do_probe_ddc_edid
                  |                                drm_edid_block_valid
                  |                                intel_hdmi_detect
                  |                                drm_target_preferred.clone.9
                  |                                process_one_work
                  |                                worker_thread
                  |                                kthread
                  |                                kernel_thread_helper
                  |          
                   --0.88%-- i2c_bit_add_numbered_bus