https://bugs.freedesktop.org/show_bug.cgi?id=104082
--- Comment #48 from Barto mister.freeman@laposte.net --- 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