linux-kernel - Re: [RFC][PATCH 11/30] ACPI / hotplug / PCI: Register all devices under the given bridge

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Date:	Fri, 12 Jul 2013 16:01:59 +0300
From:	Mika Westerberg <mika.westerberg@...ux.intel.com>
To:	"Rafael J. Wysocki" <rjw@...k.pl>
Cc:	ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Linux PCI <linux-pci@...r.kernel.org>,
	Yinghai Lu <yinghai@...nel.org>, Jiang Liu <liuj97@...il.com>
Subject: Re: [RFC][PATCH 11/30] ACPI / hotplug / PCI: Register all devices
 under the given bridge

On Fri, Jul 12, 2013 at 02:54:20PM +0300, Mika Westerberg wrote:
> On Fri, Jul 12, 2013 at 01:50:29AM +0200, Rafael J. Wysocki wrote:
> > @@ -1210,6 +1125,35 @@ void acpiphp_enumerate_slots(struct pci_
> >  	 */
> >  	get_device(&bus->dev);
> >  
> > +	if (!pci_is_root_bus(bridge->pci_bus)) {
> > +		struct acpiphp_context *context;
> > +
> > +		/*
> > +		 * This bridge should have been registered as a hotplug function
> > +		 * under its parent, so the context has to be there.  If not, we
> > +		 * are in deep goo.
> > +		 */
> > +		mutex_lock(&acpiphp_context_lock);
> > +		context = acpiphp_get_context(handle);
> > +		if (WARN_ON(!context || !context->func)) {
> > +			mutex_unlock(&acpiphp_context_lock);
> > +			put_device(&bus->dev);
> > +			kfree(bridge);
> > +			return;
> > +		}
> > +		bridge->context = context;
> > +		context->bridge = bridge;
> > +		/* Get a reference to the parent bridge. */
> > +		get_bridge(context->func->slot->bridge);
> > +		mutex_unlock(&acpiphp_context_lock);
> > +	}
> > +
> > +	status = acpi_get_handle(bridge->handle, "_EJ0", &handle);
> > +	if (ACPI_SUCCESS(status)) {
> > +		dbg("found ejectable p2p bridge\n");
> > +		bridge->flags |= BRIDGE_HAS_EJ0;
> > +	}
> > +
> >  	/* must be added to the list prior to calling register_slot */
> >  	mutex_lock(&bridge_mutex);
> >  	list_add(&bridge->list, &bridge_list);
> > @@ -1220,34 +1164,9 @@ void acpiphp_enumerate_slots(struct pci_
> >  				     register_slot, NULL, bridge, NULL);
> >  	if (ACPI_FAILURE(status)) {
> >  		acpi_handle_err(bridge->handle, "failed to register slots\n");
> > -		goto err;
> > -	}
> > -
> > -	if (pci_is_root_bus(bridge->pci_bus))
> > -		return;
> > -
> > -	status = acpi_get_handle(bridge->handle, "_EJ0", &handle);
> > -	if (ACPI_SUCCESS(status)) {
> > -		dbg("found ejectable p2p bridge\n");
> > -		bridge->flags |= BRIDGE_HAS_EJ0;
> > -	}
> > -	if (context->handler_for_func) {
> > -		/* Notify handler already installed. */
> > -		get_bridge(context->func->slot->bridge);
> > -		return;
> > +		cleanup_bridge(bridge);
> > +		put_bridge(bridge);
> >  	}
> > -
> > -	/* install notify handler for P2P bridges */
> > -	status = acpi_install_notify_handler(bridge->handle, ACPI_SYSTEM_NOTIFY,
> > -					     handle_hotplug_event, NULL);
> 
> With this removed we now install notify handlers for the slot objects under
> this bridge but not for the bridge itself.
> 
> In case of Thunderbolt the BIOS will send the event for the root port ACPI
> device \_SB_.PCI0.RP05 and with the above change we don't handle it
> anymore.

Actually there was a bug in patch [23/30] that caused this. Once that is
fixed I can see that the notify handlers get correctly installed. I'll
comment on that patch.
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