Re: ACPI / dock: ThinkPad X220: \_SB_.PCI0.LPC_.EC__.BAT1: Unable to dock!

Paul Bolle
2014-07-29T22:02:56Z

Shaohua,

Could you please update your email address in MAINTAINERS?

Thanks,

Paul Bolle

On Tue, 2014-07-29 at 23:46 +0200, Paul Bolle wrote:
> 0) A ThinkPad X220 I use prints this error at the _first_ resume from
> suspend (to ram):
> ACPI: \_SB_.PCI0.LPC_.EC__.BAT1: Unable to dock!
>
> 1) BAT1 is apparently a "battery bay". Rubin suggested that it is a
> "slice" battery. I do not use a "slice" battery. (There are two other
> possible docks according to the ACPI printks is get. An "ata bay" and a
> "dock station". I don't use those either, but the kernel at least prints
> no errors about them.)
>
> 2) I've peeked a bit at the DSDT of this machine. Its _WAK method
> contains this line:
> \_SB.PCI0.LPC.EC.BATW (Arg0)
>
> That BATW method is about 12 lines long. (Can I quote that in full?) It
> ends with this snippet:
> If (XOr (Local0, Local1))
> {
> Store (Local1, [...])
> Notify (\_SB.PCI0.LPC.EC.BAT1, 0x01) // Device Check
> }
>
> 3) That ACPI_NOTIFY_DEVICE_CHECK for BAT1 apparently triggers this call
> chain:
> acpi_bus_notify()
> acpi_hotplug_schedule()
> acpi_hotplug_work_fn()
> acpi_device_hotplug()
> dock_notify()
>
> 4) Perhaps Lenovo needs to update the ACPI part of this laptop's
> firmware. (I'm running the latest firmware.) Does Lenovo listen to
> suggestions to update its firmware?
>
> 5) A workaround in the kernel _might_ be something utterly untested like
> this:
>
> diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
> index d9339b442a4e..9e5856a6adfb 100644
> --- a/drivers/acpi/dock.c
> +++ b/drivers/acpi/dock.c
> @@ -333,7 +333,7 @@ static void dock_event(struct dock_station *ds, u32 event, int num)
> *
> * Execute the _DCK method in response to an acpi event
> */
> -static void handle_dock(struct dock_station *ds, int dock)
> +static acpi_status handle_dock(struct dock_station *ds, int dock)
> {
> acpi_status status;
> struct acpi_object_list arg_list;
> @@ -351,11 +351,12 @@ static void handle_dock(struct dock_station *ds, int dock)
> if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
> acpi_handle_err(ds->handle, "Failed to execute _DCK (0x%x)\n",
> status);
> + return status;
> }
>
> -static inline void dock(struct dock_station *ds)
> +static inline acpi_status dock(struct dock_station *ds)
> {
> - handle_dock(ds, 1);
> + return handle_dock(ds, 1);
> }
>
> static inline void undock(struct dock_station *ds)
> @@ -471,8 +472,12 @@ int dock_notify(struct acpi_device *adev, u32 event)
> case ACPI_NOTIFY_BUS_CHECK:
> case ACPI_NOTIFY_DEVICE_CHECK:
> if (!dock_in_progress(ds) && !acpi_device_enumerated(adev)) {
> + acpi_status status;
> +
> begin_dock(ds);
> - dock(ds);
> + status = dock(ds);
> + if (status == AE_NOT_FOUND)
> + break;
> if (!dock_present(ds)) {
> acpi_handle_err(handle, "Unable to dock!\n");
> complete_dock(ds);
>
> Please note that BAT1 does have a _EJ0 method but doesn't have a _DCK
> method.
>
> 6) Any suggestions?
>
>
> Paul Bolle