]> git.ipfire.org Git - thirdparty/kernel/linux.git/commit
ACPI: resources: Add checks for ACPI IRQ override
authorHui Wang <hui.wang@canonical.com>
Wed, 9 Jun 2021 02:14:42 +0000 (10:14 +0800)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Wed, 9 Jun 2021 12:39:11 +0000 (14:39 +0200)
commit0ec4e55e9f571f08970ed115ec0addc691eda613
treebcd078c8bd135825c0fa92da70d17a62c276df81
parent614124bea77e452aa6df7a8714e8bc820b489922
ACPI: resources: Add checks for ACPI IRQ override

The laptop keyboard doesn't work on many MEDION notebooks, but the
keyboard works well under Windows and Unix.

Through debugging, we found this log in the dmesg:

 ACPI: IRQ 1 override to edge, high
 pnp 00:03: Plug and Play ACPI device, IDs PNP0303 (active)

 And we checked the IRQ definition in the DSDT, it is:

    IRQ (Level, ActiveLow, Exclusive, )
        {1}

So the BIOS defines the keyboard IRQ to Level_Low, but the Linux
kernel override it to Edge_High. If the Linux kernel is modified
to skip the IRQ override, the keyboard will work normally.

From the existing comment in acpi_dev_get_irqresource(), the override
function only needs to be called when IRQ() or IRQNoFlags() is used
to populate the resource descriptor, and according to Section 6.4.2.1
of ACPI 6.4 [1], if IRQ() is empty or IRQNoFlags() is used, the IRQ
is High true, edge sensitive and non-shareable. ACPICA also assumes
that to be the case (see acpi_rs_set_irq[] in rsirq.c).

In accordance with the above, check 3 additional conditions
(EdgeSensitive, ActiveHigh and Exclusive) when deciding whether or
not to treat an ACPI_RESOURCE_TYPE_IRQ resource as "legacy", in which
case the IRQ override is applicable to it.

Link: https://uefi.org/specs/ACPI/6.4/06_Device_Configuration/Device_Configuration.html#irq-descriptor
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=213031
BugLink: http://bugs.launchpad.net/bugs/1909814
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reported-by: Manuel Krause <manuelkrause@netscape.net>
Tested-by: Manuel Krause <manuelkrause@netscape.net>
Signed-off-by: Hui Wang <hui.wang@canonical.com>
[ rjw: Subject rewrite, changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
drivers/acpi/resource.c