The same issue happened with me when i updated from blender 2.80 to 2.82a today. I had turned on OpenCL GPU rendering in cycles, viewport samples were at 32. As soon as the viewport rendered at the final sample, the whole software freezed and i had to restart my laptop. Also, the rendered samples in the viewport were white matte, not showing any of the materials/textures applied. I am using AMD Radeon R4 Graphics which has a GCN architecture support.
Have attatched the debug logs, system info and a screenshot of the viewport while rendering. Hope it is fixed soon.