TWx Linux Repository
0ec4e55e9f
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 # [1]
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>
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| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.