Messages in this thread Patch in this message | | | Date | Tue, 11 Feb 2014 12:42:37 +0200 | From | Mika Westerberg <> | Subject | Re: 3.12: ethernet controller missing after resuming from suspend to RAM |
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On Mon, Feb 10, 2014 at 11:39:29PM +0100, Rafael J. Wysocki wrote: > > _STA() returns 0x0A instead of 0x0F. Could there be something missing in > > the ACPI hotplug code that overlooks this and removes the device on resume? > > That is possible. Actually even quite likely, but let's wait for the response > from Peter.
Here's a hack that should take the 0xa return value into consideration. It turned out that this case is even mentioned in the ACPI spec.
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c index e2a783fdb98f..014381b42d86 100644 --- a/drivers/pci/hotplug/acpiphp_glue.c +++ b/drivers/pci/hotplug/acpiphp_glue.c @@ -730,6 +730,17 @@ static unsigned int get_slot_status(struct acpiphp_slot *slot) return (unsigned int)sta; } +static inline bool device_sta_valid(unsigned long long sta) +{ + /* + * ACPI spec says that _STA may return bit 0 clear with bit 8 set + * if the device is valid but does not require device driver to be + * loaded (chapter 6.3.7). + */ + unsigned mask = ACPI_STA_DEVICE_ENABLED | ACPI_STA_DEVICE_FUNCTIONING; + return (sta & mask) == mask; +} + /** * trim_stale_devices - remove PCI devices that are not responding. * @dev: PCI device to start walking the hierarchy from. @@ -745,7 +756,7 @@ static void trim_stale_devices(struct pci_dev *dev) unsigned long long sta; status = acpi_evaluate_integer(handle, "_STA", NULL, &sta); - alive = (ACPI_SUCCESS(status) && sta == ACPI_STA_ALL) + alive = (ACPI_SUCCESS(status) && device_sta_valid(sta)) || acpiphp_no_hotplug(handle); } if (!alive) { @@ -792,7 +803,7 @@ static void acpiphp_check_bridge(struct acpiphp_bridge *bridge) mutex_lock(&slot->crit_sect); if (slot_no_hotplug(slot)) { ; /* do nothing */ - } else if (get_slot_status(slot) == ACPI_STA_ALL) { + } else if (device_sta_valid(get_slot_status(slot))) { /* remove stale devices if any */ list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list)
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