From 887502826549caa7e4215fd9e628f48f14c0825a Mon Sep 17 00:00:00 2001

From: "Jason A. Donenfeld" <Jason@zx2c4.com>

Date: Thu, 30 Jun 2022 14:16:54 +0200

Subject: [PATCH] powerpc/powernv: delay rng platform device creation until

 later in boot

References: bsc#1065729

Patch-mainline: v5.19-rc6

Git-commit: 887502826549caa7e4215fd9e628f48f14c0825a

The platform device for the rng must be created much later in boot.

Otherwise it tries to connect to a parent that doesn't yet exist,

resulting in 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 platform device creation inside

of machine_subsys_initcall.

Fixes: f3eac426657d ("powerpc/powernv: wire up rng during setup_arch")

Cc: stable@vger.kernel.org

Reported-by: Sachin Sant <sachinp@linux.ibm.com>

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Tested-by: Sachin Sant <sachinp@linux.ibm.com>

[mpe: Change "of node" to "platform device" in change log]

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Link: https://lore.kernel.org/r/20220630121654.1939181-1-Jason@zx2c4.com

Acked-by: Michal Suchanek <msuchanek@suse.de>

---

 arch/powerpc/platforms/powernv/rng.c | 16 ++++++++++------

 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/rng.c b/arch/powerpc/platforms/powernv/rng.c

index 463c78c52cc5..3805ad13b8f3 100644

--- a/arch/powerpc/platforms/powernv/rng.c

+++ b/arch/powerpc/platforms/powernv/rng.c

@@ -176,12 +176,8 @@ static int __init pnv_get_random_long_early(unsigned long *v)

 		    NULL) != pnv_get_random_long_early)

 		return 0;

-	for_each_compatible_node(dn, NULL, "ibm,power-rng") {

-		if (rng_create(dn))

-			continue;

-		/* Create devices for hwrng driver */

-		of_platform_device_create(dn, NULL, NULL);

-	}

+	for_each_compatible_node(dn, NULL, "ibm,power-rng")

+		rng_create(dn);

 	if (!ppc_md.get_random_seed)

 		return 0;

@@ -205,10 +201,18 @@ void __init pnv_rng_init(void)

 static int __init pnv_rng_late_init(void)

 {

+	struct device_node *dn;

 	unsigned long v;

+

 	/* In case it wasn't called during init for some other reason. */

 	if (ppc_md.get_random_seed == pnv_get_random_long_early)

 		pnv_get_random_long_early(&v);

+

+	if (ppc_md.get_random_seed == powernv_get_random_long) {

+		for_each_compatible_node(dn, NULL, "ibm,power-rng")

+			of_platform_device_create(dn, NULL, NULL);

+	}

+

 	return 0;

 }

 machine_subsys_initcall(powernv, pnv_rng_late_init);

-- 

2.35.3