@m3x
there were some lock ups with the DMA under linux with newer Kernels if I recall correctly .
https://lore.kernel.org/lkml/146126254 ... evchenko@linux.intel.com/
Also GART seem to be enabled but ring test for hardware acceleration failed .
[ 3.121797] [drm] radeon: dpm initialized
[ 3.128222] [drm] Found VCE firmware/feedback version 50.0.1 / 17!
[ 3.134469] [drm] GART: num cpu pages 524288, num gpu pages 524288
[ 3.151139] [drm] probing gen 2 caps for device aaa1:bed1 = 18cc41/0
[ 3.210767] [drm] PCIE GART of 2048M enabled (table at 0x00000000002E8000).
[ 3.218077] radeon 0000:81:00.0: WB enabled
[ 3.222320] radeon 0000:81:00.0: fence driver on ring 0 use gpu addr 0x0000000040000c00 and cpu addr 0xee962c00
[ 3.232441] radeon 0000:81:00.0: fence driver on ring 1 use gpu addr 0x0000000040000c04 and cpu addr 0xee962c04
[ 3.242562] radeon 0000:81:00.0: fence driver on ring 2 use gpu addr 0x0000000040000c08 and cpu addr 0xee962c08
[ 3.252683] radeon 0000:81:00.0: fence driver on ring 3 use gpu addr 0x0000000040000c0c and cpu addr 0xee962c0c
[ 3.262805] radeon 0000:81:00.0: fence driver on ring 4 use gpu addr 0x0000000040000c10 and cpu addr 0xee962c10
[ 3.304324] radeon 0000:81:00.0: fence driver on ring 5 use gpu addr 0x0000000000075a18 and cpu addr 0xf5135a18
[ 3.341458] radeon 0000:81:00.0: fence driver on ring 6 use gpu addr 0x0000000040000c18 and cpu addr 0xee962c18
[ 3.351618] radeon 0000:81:00.0: fence driver on ring 7 use gpu addr 0x0000000040000c1c and cpu addr 0xee962c1c
[ 3.361759] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[ 3.368404] [drm] Driver supports precise vblank timestamp query.
[ 3.374523] radeon 0000:81:00.0: radeon: MSI limited to 32-bit
[ 3.380446] genirq: Setting trigger mode 3 for irq 45 failed (uic_set_irq_type+0x0/0x160)
[ 3.388716] radeon 0000:81:00.0: radeon: using MSI.
[ 3.393673] [drm] radeon: irq initialized.
[ 4.152902] [drm:r600_ring_test] *ERROR* radeon: ring 0 test failed (scratch(0x850C)=0xCAFEDEAD)
[ 4.161744] radeon 0000:81:00.0: disabling GPU acceleration