From 07e84aa98f6b3a7278d3267f6f657955ed3eb973 Mon Sep 17 00:00:00 2001 From: Alan Jenkins Date: Fri, 28 Aug 2009 12:56:34 +0000 Subject: [PATCH] eeepc-laptop: fix pci hotplug race on load and unload 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 Signed-off-by: Corentin Chary Signed-off-by: Len Brown --- drivers/platform/x86/eeepc-laptop.c | 77 +++++++++++++++++------------ 1 file changed, 45 insertions(+), 32 deletions(-) diff --git a/drivers/platform/x86/eeepc-laptop.c b/drivers/platform/x86/eeepc-laptop.c index 179010386981..8dd86f73b844 100644 --- a/drivers/platform/x86/eeepc-laptop.c +++ b/drivers/platform/x86/eeepc-laptop.c @@ -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(); -- GitLab