Hello,
I get the following warning during v5.1-rc3 bootup on QEMU with virtio-gpu-pci
BUG: sleeping function called from invalid context at mm/slab.h:418 in_atomic(): 1, irqs_disabled(): 0, pid: 14, name: kworker/0:1 Preemption disabled at: virtio_gpu_cmd_get_edid_cb+0x4c/0x9c CPU: 0 PID: 14 Comm: kworker/0:1 Not tainted 5.1.0-rc3-00007-g2c6e21bcbbae #6 Workqueue: events virtio_gpu_dequeue_ctrl_func Call Trace: ___might_sleep+0xfc/0x11c __might_sleep+0x42/0x64 __kmalloc+0x66/0x1f0 kvmalloc_node+0x66/0x7c drm_property_create_blob$part$0+0x14/0x8c drm_property_replace_global_blob+0x40/0xdc drm_connector_update_edid_property+0x58/0x74 virtio_gpu_cmd_get_edid_cb+0x62/0x9c virtio_gpu_dequeue_ctrl_func+0xd1/0x188 process_one_work+0x1a0/0x388 worker_thread+0x1e8/0x3b4 kthread+0xe8/0x100 ret_from_kernel_thread+0xc/0x18
Looks like virtio_gpu_cmd_get_edid_cb calls drm_connector_update_edid_property under the spinlock and the latter function may sleep.