On Tuesday 11 February 2014 12:42:37 Mika Westerberg wrote:
> 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.
Tested-by: Peter Wu <lekenst...@gmail.com>
This works, the devices are not lost anymore after resume. dmesg
mentions the 04:00.* devices at resume compared to the unpatched kernel:
[ 42.650721] PM: Finishing wakeup.
[ 42.650768] acpiphp_glue: hotplug_event: Bus check notify on \_SB_.PCI0.RP03
[ 42.650772] acpiphp_glue: hotplug_event: re-enumerating slots under
\_SB_.PCI0.RP03
[ 42.650874] iwlwifi 0000:05:00.0: no hotplug settings from platform
[ 42.650722] Restarting tasks ... done.
[ 42.650985] video LNXVIDEO:00: Restoring backlight state
[ 42.650988] video LNXVIDEO:01: Restoring backlight state
[ 43.124208] ACPI: \_SB_.AC__: ACPI_NOTIFY_BUS_CHECK event: unsupported
[ 43.128401] jme 0000:04:00.5: irq 50 for MSI/MSI-X
[ 43.153005] jme 0000:04:00.5 eth0: Link is down
[ 43.153030] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 43.154364] iwlwifi 0000:05:00.0: L1 Enabled; Disabling L0S
[ 43.162307] iwlwifi 0000:05:00.0: Radio type=0x1-0x3-0x1
[ 43.276220] acpiphp_glue: hotplug_event: Bus check notify on \_SB_.PCI0.RP01
[ 43.276223] acpiphp_glue: hotplug_event: re-enumerating slots under
\_SB_.PCI0.RP01
[ 43.276257] xhci_hcd 0000:02:00.0: no hotplug settings from platform
[ 43.276267] acpiphp_glue: hotplug_event: Bus check notify on \_SB_.PCI0.RP02
[ 43.276268] acpiphp_glue: hotplug_event: re-enumerating slots under
\_SB_.PCI0.RP02
[ 43.276355] sdhci-pci 0000:04:00.0: no hotplug settings from platform
[ 43.276368] pci 0000:04:00.2: no hotplug settings from platform
[ 43.276381] jmb38x_ms 0000:04:00.3: no hotplug settings from platform
[ 43.276393] jme 0000:04:00.5: no hotplug settings from platform
[ 43.276398] acpiphp_glue: hotplug_event: Bus check notify on \_SB_.PCI0.RP03
[ 43.276399] acpiphp_glue: hotplug_event: re-enumerating slots under
\_SB_.PCI0.RP03
[ 43.276491] iwlwifi 0000:05:00.0: no hotplug settings from platform
[ 43.277214] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
Rafael, do you want me to test the other patch as well?
Peter
> 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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