Bug 15605
| Summary: | \_SB_ is not the only root-level namespace device - introduced by commit 78b8e141 | ||
|---|---|---|---|
| Product: | ACPI | Reporter: | Zhang Rui (rui.zhang) |
| Component: | BIOS | Assignee: | Bjorn Helgaas (bjorn.helgaas) |
| Status: | CLOSED PATCH_ALREADY_AVAILABLE | ||
| Severity: | high | CC: | bjorn.helgaas, lenb, yong.y.wang |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 2.6.32-rc1 and later | Subsystem: | |
| Regression: | Yes | Bisected commit-id: | |
| Attachments: |
DSDT that has device AMW0 as a root-level namespace device
patch for testing (use _HID when present) patch: set ACPI_BUS_HID to \_SB only patch from comment #2 as applied to 2.6.34-rc3 |
||
Created attachment 25644 [details]
patch for testing (use _HID when present)
Thanks for debugging and reporting this!
The assumption that all root-level devices are \_SB devices was there long before 78b8e141, but the implementation was broken (it compared an acpi_device pointer with a handle, which was never true), so we never saw any LNXSYBUS devices at all.
After I fixed the implementation in 78b8e141, we gave LNXSYBUS HIDs to *all* root-level devices, which isn't quite right either.
Can you test this patch, please?
I just tested this patch and it works for me. Thanks for the patch, Helgaas! Rui, could you please asn lenb to queue up this patch? with this patch applied, LNXSYBUS is assigned to \AMW0 as a cid.
I don't think this is what we want.
perhaps something like this?
- acpi_add_id(device, ACPI_BUS_HID);
- strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
- strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
- break;
+ if (strncmp(device->pnp.bus_id, "SB", 3) &&
+ strncmp(device->pnp.bus_id, "SB_", 4) &&
+ strncmp(device->pnp.bus_id, "_SB", 4) &&
+ strncmp(device->pnp.bus_id, "_SB_", 4)) {
+ acpi_add_id(device, ACPI_BUS_HID);
+ strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
+ strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
+ break;
+ }
Created attachment 25650 [details]
patch: set ACPI_BUS_HID to \_SB only
Hi, Bjorn, how about this one?
Yong,
will you please apply this patch and see if it helps?
Rui, I just tried your patch and it works too. Did you verify that LNXSYBUS is assigned to \AMW0 as a CID?
Just from reading the code in attachment 25644 [details], I don't see how that would happen. \AMW0 has a valid _HID, so we'll assign PNP0C14 first, and then acpi_device_hid() will return a valid pointer, so we shouldn't add ACPI_BUS_HID.
(In reply to comment #6) > Did you verify that LNXSYBUS is assigned to \AMW0 as a CID? > > Just from reading the code in attachment 25644 [details], I don't see how > that would > happen. \AMW0 has a valid _HID, so we'll assign PNP0C14 first, and then > acpi_device_hid() will return a valid pointer, so we shouldn't add > ACPI_BUS_HID. that's right. sorry for the mistake. Acked-by: Zhang Rui <rui.zhang@intel.com> Created attachment 25843 [details] patch from comment #2 as applied to 2.6.34-rc3 commit b7b30de53aef6ce773d34837ba7d8422bd3baeec Author: Bjorn Helgaas <bjorn.helgaas@hp.com> Date: Wed Mar 24 10:44:33 2010 -0600 ACPI: use _HID when supplied by root-level devices shipped in linux-2.6.34-rc4 closed |
Created attachment 25636 [details] DSDT that has device AMW0 as a root-level namespace device In commit 78b8e141, we assume all the root-level namespace devices are \_SB devices. But this is not true. Here is part of the output of "grep . /sys/bus/acpi/devices/*/path" in 2.6.33 /sys/bus/acpi/devices/LNXSYSTM:00/LNXSYBUS:00/path:\_SB_ /sys/bus/acpi/devices/LNXSYSTM:00/LNXSYBUS:01/path:\AMW0 and here is the output of "grep . /sys/bus/acpi/drivers/wmi/*/path" in 2.6.31 /sys/bus/acpi/drivers/wmi/PNP0C14:00/path:\AMW0 device \AMW0 is renamed and the ACPI wmi driver is not bind to it any more.