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eeepc-laptop: fix pci hotplug race on load and unload

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Wifi rfkill state changes can race with pci hotplug cleanup.  A simple
fix is to refresh the hotplug state just before deregistering the pci
hotplug slot.

There is also potential for a hotplug notification to fire too early
during setup, while the structures it uses are still being initialised.
(This could only happen if the BIOS performs hotplug itself; a bug
triggered by removing the battery while hibernated).  Avoid this by
registering the notifier later.  The same refresh mechanism is used
to handle rfkill state changes which can now race with registration.

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Alan Jenkins 2009-08-28 12:56:34 +00:00 committed by Len Brown
parent dcf443b581
commit 07e84aa98f
1 changed files with 45 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

77
drivers/platform/x86/eeepc-laptop.c
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@ -667,37 +667,37 @@ static void eeepc_rfkill_hotplug(void)
struct pci_bus *bus;
bool blocked = eeepc_wlan_rfkill_blocked();
rfkill_set_sw_state(ehotk->wlan_rfkill, blocked);
if (ehotk->wlan_rfkill)
rfkill_set_sw_state(ehotk->wlan_rfkill, blocked);
mutex_lock(&ehotk->hotplug_lock);
if (ehotk->hotplug_slot == NULL)
goto out_unlock;
bus = pci_find_bus(0, 1);
if (!bus) {
pr_warning("Unable to find PCI bus 1?\n");
goto out_unlock;
}
if (!blocked) {
dev = pci_get_slot(bus, 0);
if (dev) {
/* Device already present */
pci_dev_put(dev);
if (ehotk->hotplug_slot) {
bus = pci_find_bus(0, 1);
if (!bus) {
pr_warning("Unable to find PCI bus 1?\n");
goto out_unlock;
}
dev = pci_scan_single_device(bus, 0);
if (dev) {
pci_bus_assign_resources(bus);
if (pci_bus_add_device(dev))
pr_err("Unable to hotplug wifi\n");
}
} else {
dev = pci_get_slot(bus, 0);
if (dev) {
pci_remove_bus_device(dev);
pci_dev_put(dev);
if (!blocked) {
dev = pci_get_slot(bus, 0);
if (dev) {
/* Device already present */
pci_dev_put(dev);
goto out_unlock;
}
dev = pci_scan_single_device(bus, 0);
if (dev) {
pci_bus_assign_resources(bus);
if (pci_bus_add_device(dev))
pr_err("Unable to hotplug wifi\n");
}
} else {
dev = pci_get_slot(bus, 0);
if (dev) {
pci_remove_bus_device(dev);
pci_dev_put(dev);
}
}
}
@ -1029,14 +1029,22 @@ static void eeepc_rfkill_exit(void)
{
eeepc_unregister_rfkill_notifier("\\_SB.PCI0.P0P6");
eeepc_unregister_rfkill_notifier("\\_SB.PCI0.P0P7");
if (ehotk->wlan_rfkill)
if (ehotk->wlan_rfkill) {
rfkill_unregister(ehotk->wlan_rfkill);
ehotk->wlan_rfkill = NULL;
}
/*
* Refresh pci hotplug in case the rfkill state was changed after
* eeepc_unregister_rfkill_notifier()
*/
eeepc_rfkill_hotplug();
if (ehotk->hotplug_slot)
pci_hp_deregister(ehotk->hotplug_slot);
if (ehotk->bluetooth_rfkill)
rfkill_unregister(ehotk->bluetooth_rfkill);
if (ehotk->wwan3g_rfkill)
rfkill_unregister(ehotk->wwan3g_rfkill);
if (ehotk->hotplug_slot)
pci_hp_deregister(ehotk->hotplug_slot);
}
static void eeepc_input_exit(void)
@ -1104,9 +1112,6 @@ static int eeepc_rfkill_init(struct device *dev)
mutex_init(&ehotk->hotplug_lock);
eeepc_register_rfkill_notifier("\\_SB.PCI0.P0P6");
eeepc_register_rfkill_notifier("\\_SB.PCI0.P0P7");
result = eeepc_new_rfkill(&ehotk->wlan_rfkill,
"eeepc-wlan", dev,
RFKILL_TYPE_WLAN, CM_ASL_WLAN);
@ -1136,6 +1141,14 @@ static int eeepc_rfkill_init(struct device *dev)
if (result == -EBUSY)
result = 0;
eeepc_register_rfkill_notifier("\\_SB.PCI0.P0P6");
eeepc_register_rfkill_notifier("\\_SB.PCI0.P0P7");
/*
* Refresh pci hotplug in case the rfkill state was changed during
* setup.
*/
eeepc_rfkill_hotplug();
exit:
if (result && result != -ENODEV)
eeepc_rfkill_exit();