Skip to main content

[Follow-up] Quest of enabling hotkeys on ASUS Laptops

Resuming for the previous topic, with the help of an Arch user and one of kernel maintainers, it turned out the failure of hotkeys functions [Fn] is due to a Linux ACPI bug. Further investigation revealed a bad practice from BIOS vendor and unexpectedly a new challenge in Linux kernel world as quoted:
However this report indicates us another gap (except the enumeration order gap):
If the namespace EC (DSDT EC in short) is not ready, EC access availability can be kept 
using the ECDT EC. In Linux, that requres _Qxx control methods to be registered for
the ECDT EC. I have never seen a Linux EC driver version doing this before,
_Qxx registration is only invoked in acpi_ec_add(). So this bug indicates a gap for Linux.
Essentially, what is initially a bug related for non-functional hotkeys for ASUS X550Z laptop revealed a much more deeper issue related Linux ACPI. It is the first time I reached that level of testing in kernel world with the help from upstream kernel.

A built kernel with an attempt patch to resolve ACPI EC problem is on COPR repository. It willl take longer to complete before testing the patch which will hopefully restore hotkeys functionality on some modern laptops especially ASUS. A suivre...

Comments

Popular posts from this blog

Getting ready for Vanlug

Busy weekend. I just took a break for making a presentation of Fedora Core 6 and Fedora Project for Vancouver Linux Users Group which will debut on November 20, 2006. A local computer store was kind enough to give me a laptop for the demonstration of Fedora Core 6 (Zod) live spin and Sugar interface from OLPC Project. Should you be interested to view that event and live near Vancouver, here is the address .

Drawing hair with Inkscape

My very first online tutorial is an adaption from Chris Design Drawing Hairs article using both Path and Path Editor tools which requires Inkscape 0.47 or newer. Start-up Inkscape application which should open a new blank page and set the document into landscape.  Create a path Select the bezier tool or press either Shift+F6 or B on the keyboard. Draw a line to approximately 800px or more. You can also use rectangle tool ( R or F4 as shortcut key) as a thin line illustrated in grey. While the line is selected, convert into path from the menu Path -> Stroke to Path or press Ctrl+Alt+C on the keyboard. For the rectangle, Path -> Object to Path or Ctrl+Shift+C . The result will show grey diamonds on each corner. Create a pattern On the menu, Extensions -> Modify Paths -> Add Nodes . Set the Max Segments Length to 5px. On the menu Extension -> Modify Paths -> Jitter Nodes . Leave the default settings and apply effects.

HP, Linux and ACPI

 Majority of HP hardware running on Linux and even Microsoft reported an issue related to a non-standard compliant ACPI. Notable message below repeats at least three times on the boot: 4.876549] ACPI BIOS Error (bug): AE_AML_BUFFER_LIMIT, Field [D128] at bit offset/length 128/1024 exceeds size of target Buffer (160 bits) (20190215/dsopcode-198)  [ 4.876555] ACPI Error: Aborting method \HWMC due to previous error (AE_AML_BUFFER_LIMIT) (20190215/psparse-529)  [ 4.876562] ACPI Error: Aborting method \_SB.WMID.WMAA due to previous error (AE_AML_BUFFER_LIMIT) (20190215/psparse-529) The bug is a known for years from which Linux kernel team are unable to fix without the help of vendor i.e. HP. Here is a compilation of reports: BIOS error: The BIOS in this system is not fully ACPI compliant. ACPI BIOS ERROR (blue screen) on startup   ACPI bad works with Linux    The good news is some errors seems harmless. Unfortunately, such errors displayed the quirks approach used by