Commit 8c6a0a1f authored Jun 15, 2016 by Greg Kurz Committed by Michael Ellerman Jul 08, 2016

powerpc/pseries: start rtasd before PCI probing



A strange behaviour is observed when comparing PCI hotplug in QEMU, between
x86 and pseries. If you consider the following steps:
- start a VM
- add a PCI device via the QEMU monitor before the rtasd has started (for
  example starting the VM in paused state, or hotplug during FW or boot
  loader)
- resume the VM execution

The x86 kernel detects the PCI device, but the pseries one does not.

This happens because the rtasd kernel worker is currently started under
device_initcall, while PCI probing happens earlier under subsys_initcall.

As a consequence, if we have a pending RTAS event at boot time, a message
is printed and the event is dropped.

This patch moves all the initialization of rtasd to arch_initcall, which is
run before subsys_call: this way, logging_enabled is true when the RTAS
event pops up and it is not lost anymore.

The proc fs bits stay at device_initcall because they cannot be run before
fs_initcall.

Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

parent 63a72284

arch/powerpc/kernel/rtasd.c

+17 −5

Original line number	Diff line number	Diff line
		@@ -526,10 +526,8 @@ void rtas_cancel_event_scan(void)
		}
		EXPORT_SYMBOL_GPL(rtas_cancel_event_scan);

		static int __init rtas_init(void)
		static int __init rtas_event_scan_init(void)
		{
		struct proc_dir_entry *entry;

		if (!machine_is(pseries) && !machine_is(chrp))
		return 0;

		@@ -562,13 +560,27 @@ static int __init rtas_init(void)
		return -ENOMEM;
		}

		start_event_scan();

		return 0;
		}
		arch_initcall(rtas_event_scan_init);

		static int __init rtas_init(void)
		{
		struct proc_dir_entry *entry;

		if (!machine_is(pseries) && !machine_is(chrp))
		return 0;

		if (!rtas_log_buf)
		return -ENODEV;

		entry = proc_create("powerpc/rtas/error_log", S_IRUSR, NULL,
		&proc_rtas_log_operations);
		if (!entry)
		printk(KERN_ERR "Failed to create error_log proc entry\n");

		start_event_scan();

		return 0;
		}
		__initcall(rtas_init);