soc: fsl: dpio: register dpio irq handlers after dpio create

The dpio irqs must be registered when you can actually
receive interrupts, ie when the dpios are created.
Kernel goes through NULL pointer dereference errors
followed by kernel panic [1] because the dpio irqs are
enabled before the dpio is created.

[1]
Unable to handle kernel NULL pointer dereference at virtual address 0040
fsl_mc_dpio dpio.14: probed
fsl_mc_dpio dpio.13: Adding to iommu group 11
  ISV = 0, ISS = 0x00000004
Unable to handle kernel NULL pointer dereference at virtual address 0040
Mem abort info:
  ESR = 0x96000004
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
Data abort info:
  ISV = 0, ISS = 0x00000004
  CM = 0, WnR = 0
[0000000000000040] user address but active_mm is swapper
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 2 PID: 151 Comm: kworker/2:1 Not tainted 5.6.0-rc4-next-20200304 #1
Hardware name: NXP Layerscape LX2160ARDB (DT)
Workqueue: events deferred_probe_work_func
pstate: 00000085 (nzcv daIf -PAN -UAO)
pc : dpaa2_io_irq+0x18/0xe0
lr : dpio_irq_handler+0x1c/0x28
sp : ffff800010013e20
x29: ffff800010013e20 x28: ffff0026d9b4c140
x27: ffffa1d38a142018 x26: ffff0026d2953400
x25: ffffa1d38a142018 x24: ffffa1d38a7ba1d8
x23: ffff800010013f24 x22: 0000000000000000
x21: 0000000000000072 x20: ffff0026d2953400
x19: ffff0026d2a68b80 x18: 0000000000000001
x17: 000000002fb37f3d x16: 0000000035eafadd
x15: ffff0026d9b4c5b8 x14: ffffffffffffffff
x13: ff00000000000000 x12: 0000000000000038
x11: 0101010101010101 x10: 0000000000000040
x9 : ffffa1d388db11e4 x8 : ffffa1d38a7e40f0
x7 : ffff0026da414f38 x6 : 0000000000000000
x5 : ffff0026da414d80 x4 : ffff5e5353d0c000
x3 : ffff800010013f60 x2 : ffffa1d388db11c8
x1 : ffff0026d2a67c00 x0 : 0000000000000000
Call trace:
 dpaa2_io_irq+0x18/0xe0
 dpio_irq_handler+0x1c/0x28
 __handle_irq_event_percpu+0x78/0x2c0
 handle_irq_event_percpu+0x38/0x90
 handle_irq_event+0x4c/0xd0
 handle_fasteoi_irq+0xbc/0x168
 generic_handle_irq+0x2c/0x40
 __handle_domain_irq+0x68/0xc0
 gic_handle_irq+0x64/0x150
 el1_irq+0xb8/0x180
 _raw_spin_unlock_irqrestore+0x14/0x48
 irq_set_affinity_hint+0x6c/0xa0
 dpaa2_dpio_probe+0x2a4/0x518
 fsl_mc_driver_probe+0x28/0x70
 really_probe+0xdc/0x320
 driver_probe_device+0x5c/0xf0
 __device_attach_driver+0x88/0xc0
 bus_for_each_drv+0x7c/0xc8
 __device_attach+0xe4/0x140
 device_initial_probe+0x18/0x20
 bus_probe_device+0x98/0xa0
 device_add+0x41c/0x758
 fsl_mc_device_add+0x184/0x530
 dprc_scan_objects+0x280/0x370
 dprc_probe+0x124/0x3b0
 fsl_mc_driver_probe+0x28/0x70
 really_probe+0xdc/0x320
 driver_probe_device+0x5c/0xf0
 __device_attach_driver+0x88/0xc0
 bus_for_each_drv+0x7c/0xc8
 __device_attach+0xe4/0x140
 device_initial_probe+0x18/0x20
 bus_probe_device+0x98/0xa0
 deferred_probe_work_func+0x74/0xa8
 process_one_work+0x1c8/0x470
 worker_thread+0x1f8/0x428
 kthread+0x124/0x128
 ret_from_fork+0x10/0x18
Code: a9bc7bfd 910003fd a9025bf5 a90363f7 (f9402015)
---[ end trace 38298e1a29e7a570 ]---
Kernel panic - not syncing: Fatal exception in interrupt
SMP: stopping secondary CPUs
Mem abort info:
  ESR = 0x96000004
  CM = 0, WnR = 0
  EC = 0x25: DABT (current EL), IL = 32 bits
[0000000000000040] user address but active_mm is swapper
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
Data abort info:
  ISV = 0, ISS = 0x00000004
  CM = 0, WnR = 0
[0000000000000040] user address but active_mm is swapper
SMP: failed to stop secondary CPUs 0-2
Kernel Offset: 0x21d378600000 from 0xffff800010000000
PHYS_OFFSET: 0xffffe92180000000
CPU features: 0x10002,21806008
Memory Limit: none
---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---
Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Grigore Popescu <grigore.popescu@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

drivers/soc/fsl/dpio/dpio-driver.c

@@ -233,10 +233,6 @@ static int dpaa2_dpio_probe(struct fsl_mc_device *dpio_dev)
 		goto err_allocate_irqs;
 	}
 
-	err = register_dpio_irq_handlers(dpio_dev, desc.cpu);
-	if (err)
-		goto err_register_dpio_irq;
-
 	priv->io = dpaa2_io_create(&desc, dev);
 	if (!priv->io) {
 		dev_err(dev, "dpaa2_io_create failed\n");
@@ -244,6 +240,10 @@ static int dpaa2_dpio_probe(struct fsl_mc_device *dpio_dev)
 		goto err_dpaa2_io_create;
 	}
 
+	err = register_dpio_irq_handlers(dpio_dev, desc.cpu);
+	if (err)
+		goto err_register_dpio_irq;
+
 	dev_info(dev, "probed\n");
 	dev_dbg(dev, "   receives_notifications = %d\n",
 		desc.receives_notifications);