ralink mt7621 attempts to use kzalloc before normal memory management is available. Before v6.1-rc1, mt7621.c soc_dev_init silently failed to kzalloc and returned in soc_dev_init, but continued to boot without the soc device registered. After, kernel crashes before it outputs any console messages This was bisected to an mm/slub change (detailed in patch 3) RFC due to - probably a (much) better way to do this - do not have mt7621 device with PCIe to test drivers/phy/ralink/phy-mt7621-pci.c - should this reference a commit as Fixes?
