[+] Description of problem: - On a laptop, if I change the display to be the additional or only HDMI, kworker begins hogging CPU to the point at which songs and videos are skipping. [+] Version-Release number of selected component (if applicable): - libdrm-2.4.70-1.fc24 - 4.7.3-200.fc24.x86_64 [+] How reproducible: - Always [+] Steps to Reproduce: 1. Install Fedora 24 on a. R7 Carrizo machine. 2. Change display output to be only HDMI. [+] Actual results: - kworker using 70-100% CPU [+] Expected results: - Normal CPU usage [+] Additional info: - I used perf to gather some info on kworker: Samples: 50K of event 'cycles', Event count (approx.): 24544555297 Children Self Command Shared Object Symbol ◆ - 75.63% 0.00% kworker/3:1 [kernel.kallsyms] [k] worker_thread ▒ - 75.63% worker_thread ▒ - 75.61% process_one_work ▒ + 75.60% amdgpu_hotplug_work_func ▒ - 75.63% 0.00% kworker/3:1 [kernel.kallsyms] [k] kthread ▒ kthread ▒ - worker_thread ▒ - 75.61% process_one_work ▒ + 75.60% amdgpu_hotplug_work_func ▒ - 75.63% 0.00% kworker/3:1 [kernel.kallsyms] [k] ret_from_fork ▒ ret_from_fork ▒ kthread ▒ - worker_thread ▒ - 75.61% process_one_work ▒ + 75.60% amdgpu_hotplug_work_func ▒ - 75.61% 0.00% kworker/3:1 [kernel.kallsyms] [k] process_one_work ▒ - process_one_work ▒ + 75.60% amdgpu_hotplug_work_func ▒ - 75.60% 0.00% kworker/3:1 [kernel.kallsyms] [k] amdgpu_connector_dp_detect ▒ + amdgpu_connector_dp_detect ▒ - 75.60% 0.00% kworker/3:1 [kernel.kallsyms] [k] drm_helper_hpd_irq_event ▒ drm_helper_hpd_irq_event ▒ + amdgpu_connector_dp_detect ▒ - 75.60% 0.00% kworker/3:1 [kernel.kallsyms] [k] amdgpu_hotplug_work_func ▒ amdgpu_hotplug_work_func ▒ drm_helper_hpd_irq_event ▒ + amdgpu_connector_dp_detect ▒ - 75.54% 0.00% kworker/3:1 [kernel.kallsyms] [k] amdgpu_atombios_encoder_set_edp_panel_power ▒ + 75.54% amdgpu_atombios_encoder_set_edp_panel_power ▒ - 64.72% 0.96% kworker/3:1 [kernel.kallsyms] [k] amdgpu_atom_execute_table_locked ▒ + 63.76% amdgpu_atom_execute_table_locked ▒ + 0.96% ret_from_fork ▒ - 64.72% 0.00% kworker/3:1 [kernel.kallsyms] [k] amdgpu_atom_execute_table ▒ amdgpu_atom_execute_table ▒ + amdgpu_atom_execute_table_locked ▒ - 64.65% 0.00% kworker/3:1 [kernel.kallsyms] [k] atom_op_calltable ▒ - atom_op_calltable ▒ + 64.46% amdgpu_atom_execute_table_locked ▒ - 62.78% 0.70% kworker/3:1 [kernel.kallsyms] [k] atom_op_test ▒ - 62.08% atom_op_test ▒ - 61.98% atom_get_src_int ▒ - 60.58% cail_reg_read ▒ 60.06% amdgpu_mm_rreg ▒ + 0.70% ret_from_fork ▒ - 62.08% 1.40% kworker/3:1 [kernel.kallsyms] [k] atom_get_src_int ▒ - 60.68% atom_get_src_int ▒ - 60.59% cail_reg_read ▒ 60.06% amdgpu_mm_rreg ▒ + 1.40% ret_from_fork ▒ - 60.68% 0.15% kworker/3:1 [kernel.kallsyms] [k] cail_reg_read ▒ - 60.53% cail_reg_read ▒ 60.06% amdgpu_mm_rreg ▒ - 60.21% 60.21% kworker/3:1 [kernel.kallsyms] [k] amdgpu_mm_rreg ▒ ret_from_fork ▒ kthread ▒ worker_thread ▒ process_one_work ▒ amdgpu_hotplug_work_func ▒ drm_helper_hpd_irq_event ▒ + amdgpu_connector_dp_detect ▒ - 10.86% 10.86% kworker/3:1 [kernel.kallsyms] [k] delay_mwaitx ▒ ret_from_fork ▒ kthread ▒ worker_thread ▒ process_one_work ▒ amdgpu_hotplug_work_func ▒ drm_helper_hpd_irq_event ▒ + amdgpu_connector_dp_detect
This happens upstream as well on the vanilla kernel, might not be anything we can do about it downstream: https://bugs.freedesktop.org/show_bug.cgi?id=97849
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Fedora 24 changed to end-of-life (EOL) status on 2017-08-08. Fedora 24 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. If you are unable to reopen this bug, please file a new report against the current release. If you experience problems, please add a comment to this bug. Thank you for reporting this bug and we are sorry it could not be fixed.