Hi Michael,

On Mon, Jul 04, 2022 at 09:14:32PM +1000, Michael Ellerman wrote:

On 2 July 2022 8:42:06 pm AEST, "Jason A. Donenfeld" [off-list ref] wrote:

quoted

Hi Benjamin, Paul,

On Thu, Jun 30, 2022 at 07:24:05PM +0530, Sachin Sant wrote:

quoted

quoted

On 30-Jun-2022, at 5:46 PM, Jason A. Donenfeld [off-list ref] wrote:

The of node for the rng must be created much later in boot. Otherwise it
tries to connect to a parent that doesn't yet exist, resulting on this
splat:

[    0.000478] kobject: '(null)' ((____ptrval____)): is not initialized, yet kobject_get() is being called.
[    0.002925] [c000000002a0fb30] [c00000000073b0bc] kobject_get+0x8c/0x100 (unreliable)
[    0.003071] [c000000002a0fba0] [c00000000087e464] device_add+0xf4/0xb00
[    0.003194] [c000000002a0fc80] [c000000000a7f6e4] of_device_add+0x64/0x80
[    0.003321] [c000000002a0fcb0] [c000000000a800d0] of_platform_device_create_pdata+0xd0/0x1b0
[    0.003476] [c000000002a0fd00] [c00000000201fa44] pnv_get_random_long_early+0x240/0x2e4
[    0.003623] [c000000002a0fe20] [c000000002060c38] random_init+0xc0/0x214

This patch fixes the issue by doing the of node creation inside of
machine_subsys_initcall.

Fixes: f3eac426657d ("powerpc/powernv: wire up rng during setup_arch")
Cc: stable@vger.kernel.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Sachin Sant <redacted>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---

Thanks Jason for the patch. This fixes the reported problem for me.

Tested-by: Sachin Sant <redacted>

- Sachin

It sounds like Michael is on vacation for a few weeks. Think you could
queue this up so we can get POWER8 booting again?

It doesn't break booting for me, but it is an ugly splat.

I'll pick it up into fixes.

I think it's more correct to say the "platform device creation" causes the problem, so I'll update the change log to say that.

Sounds good. Thank you!

Jason