root@ubuntu:~# dmesg | grep radeon
[    4.776476] [drm] radeon kernel modesetting enabled.
[    4.777531] radeon 0000:01:05.0: VRAM: 256M 0x00000000C0000000 - 0x00000000CFFFFFFF (256M used)
[    4.777533] radeon 0000:01:05.0: GTT: 512M 0x00000000A0000000 - 0x00000000BFFFFFFF
[    4.777711] [drm] radeon: 256M of VRAM memory ready
[    4.777712] [drm] radeon: 512M of GTT memory ready.
[    4.777799] [drm] radeon: power management initialized
[    4.808112] radeon 0000:01:05.0: WB enabled
[    4.808117] radeon 0000:01:05.0: fence driver on ring 0 use gpu addr 0x00000000a0000c00 and cpu addr 0xffff8800cfb0ac00
[    4.808123] radeon 0000:01:05.0: radeon: MSI limited to 32-bit
[    4.808136] [drm] radeon: irq initialized.
[    4.985367] fbcon: radeondrmfb (fb0) is primary device
[    5.055648] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery reached max voltage
[    5.055649] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery failed
[    5.080617] radeon 0000:01:05.0: fb0: radeondrmfb frame buffer device
[    5.080619] radeon 0000:01:05.0: registered panic notifier
[    5.082404] [drm] Initialized radeon 2.39.0 20080528 for 0000:01:05.0 on minor 0
[   23.927581] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery reached max voltage
[   23.927587] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery failed
[   24.580256] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery reached max voltage
[   24.580261] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery failed
[   28.943695] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery reached max voltage
[   28.943700] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery failed
[   44.196864] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery reached max voltage
[   44.196870] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery failed
[   49.578518] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery reached max voltage
[   49.578524] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery failed
[   78.514023] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery reached max voltage
[   78.514028] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery failed
[   78.550056] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery reached max voltage
[   78.550061] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery failed
[  125.882579] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery reached max voltage
[  125.882584] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery failed
[  125.918617] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery reached max voltage
[  125.918622] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery failed
[  133.865080] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery reached max voltage
[  133.865085] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery failed
[  784.794562] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery reached max voltage
[  784.794574] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery failed
[  784.822591] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery reached max voltage
[  784.822596] [drm:radeon_dp_link_train_cr] *ERROR* clock recovery failed