Product Database

Touchpads May Not Work with ABI2.0 Distros ​

Some laptops come with touchpads that are wired using an HID-over-I2C bus, which requires a GPIO pin to supply interrupts.

To resolve this issue, a patch to add interrupt support for 7A2000 GPIO is required (now part of Linux 6.15 and above, most commercial distros using Linux 6.6 also includes a fix). Additionally, as the upstream kernel no longer supports the deprecated gsi_idx_map property, a workaround is needed - see this kernel patch from AOSC OS.

Backlight Control May Not be Available with ABI2.0 Distros ​

Due to a change in upstream kernel API and problematic Loongson PWM driver implementation, as well as the lack of gpio_base support, laptop backlight control may not be available with some Linux distros.

To fix this issue, the following is needed:

• Additional board-level ACPI initialization routinesand corresponding changes to the LoongGPU kernel driver (as implemented by AOSC OS are needed - correctly calling PWM controllers and the functionality to completely turn off backlight via GPIO.
• A patch to fix PWM controller frequency calculation, see this kernel patch from AOSC OS (this patch is now part of Linux 6.18).

CPU Frequency Scaling May Not Work with Some ABI2.0 Distros ​

ABI2.0 ("New World") distros using upstream Linux kernels do not have functional CPU frequency scaling. This is due a lack of SMCv1 interface implementation in the upstream Linux kernel. ziyao233 has submitted a preliminary patch, but instability was observed during testing.

High Energy Consumption ​

Laptops that uses AVS (Adaptive Voltage Scaling) and not the full DVFS (Dynamic Voltage and Frequency Scaling) are known to have higher energy consumptions. Laptops that offers a limited range of core voltage modulation is especially prone to higher power consumption and less-than-ideal battery runtime.

Source: Bai Mingcong