acpi_prp0001=0 acpi=prp0001 0 acpi prp0001=off (not parsed; on/off are not defined)
Right-click the device in > Properties > Details .
To understand PRP0001 (often seen as acpi PRP0001:00 or ACPI\PRP0001 in Windows), it is essential to first grasp the fundamental difference between its two parent technologies. acpi prp0001 0
: A patch by Andy Shevchenko corrected device_get_match_data() to work correctly with PRP0001 devices. Previously, calling this function returned nothing because the ACPI core did not respect PRP0001 during match data retrieval.
In modern systems, ACPI PRP0001 is commonly used in conjunction with other ACPI components, such as the ACPI Power Management Unit (PMU) and the System Management Controller (SMC). These components work together to provide a comprehensive power management and configuration framework. : Mika Westerberg's commit 733e625 introduced the special
: Mika Westerberg's commit 733e625 introduced the special PRP0001 ID so that driver matching could be done using Device Tree compatible properties.
As kernel development continues, PRP0001 remains a relevant and useful feature for hardware enablement. Recent patches (2025–2026) continue to refine how PRP0001 devices are handled, including improvements to match data retrieval and handling of devices with both _HID and PRP0001 in _CID . While it is often described as a temporary solution, PRP0001 continues to serve as an essential bridge for developers bringing devices to ACPI platforms. SD card readers
PC Engines APU* LED support · Issue #2114 · opnsense/core - GitHub
: It often points to internal components like GPIO controllers , SD card readers , or audio components that rely on non-standard firmware configurations. 🛠 How to Fix the "Unknown Device"
If you use acpi=off , PRP0001 processing never starts. acpi prp0001 0 is irrelevant in that case.