On Tue, Jan 31, 2023 at 08:18:49AM +0100, Ard Biesheuvel wrote: > (cc Jason for awareness) > > On Tue, 31 Jan 2023 at 05:04, Jia He <justin.he@xxxxxxx> wrote: > > > > I met a hung task warning and then kernel was hung forever with latest > > kernel on an Ampere Emag server. > > > > The root cause is kernel was hung when invoking an efi rts call to set > > the RandomSeed variable during the booting stage. The arch_efi_call_virt > > call (set_variable) was never returned and then caused the hung task error. > > > > Given that EFI variables work on this platform (as far as I know), the > problem may be that we are calling SetVariable() too early. > On my phone and with very limited connectivity for another 10 days, but I wonder if there's a later place we could move this block: if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) execute_with_initialized_rng(&refresh_nv_rng_seed_nb); Is there any additional initialization that happens after efisubsys_init() that we're maybe missing out on there? Jason