Comment # 48 on bug 104082 from Barto

the bug occurs also with radeon driver, and not only amdgpu :

radeon 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes)
radeon 0000:01:00.0: swiotlb: coherent allocation failed, size=2097152
CPU: 1 PID: 979 Comm: Compositor Not tainted 4.16.4-1-ARCH #1

my graphic card : amd radeon HD4650 Pcie
OS: archlinux 64 bits