On Fri, Apr 23, 2021 at 10:58 PM Maximilian Luz <luzmaximilian@xxxxxxxxx> wrote: > > Hi all, > > I received a report from a Surface Laptop 4 which has a UART that is > identified as AMDI0022 in ACPI [1] and that does not seem to be > supported by the kernel yet. > > From what I can tell via ACPI, this is similar to the AMDI0020 [2] UART > that's already supported by the kernel (well, both are devices with two > MMIO regions and an interrupt as far as I can tell...). So it's possible > that all that's needed is adding it to the respective device ID lists > [3, 4]. Unfortunately, I a) don't have a device to test this myself, b) > haven't found any more details on that online, and c) don't want to tell > others to test this without knowing a bit more about that (potentially > writing random stuff to some unknown MMIO region that I don't know > anything about doesn't sound as safe to me as I'd like). To me they look completely the same. Depending on the device which is connected to the UART, I would suggest just to add an ID and see if it makes it work. > Does anyone here have some pointers on what it'd take to support this, > or any contacts at AMD that could provide more insight? -- With Best Regards, Andy Shevchenko
