Re: [PATCH] xen: acpi: Hide UART address only if SPCR exists

[Elliott Mitchell <ehem+xen@xxxxxxx>]

On Mon, Sep 28, 2020 at 09:41:39PM +0900, Masami Hiramatsu wrote:
> With Julien's ACPI fix, I found my DeveloperBox (
> https://www.96boards.org/product/developerbox/ ) still failed
> to boot bcause of SPCR issue. According to the UEFI EDK2
> implementation, the SCPR table will not be made if user
> chooses graphical console instead of serial.
> In such case, we should ignore the SPCR missing error.

You weren't the only person running into this.  Since you didn't get
back sooner I ended up submitting a pretty similar patch (I kept the
printk() due to informational value).

861f0c110976fa8879b7bf63d9478b6be83d4ab6 on master (switching to "main"
in the future?)

> Compared with Linux kernel implementation, this doesn't check
> the STAO (status override) table, becaue it seems STAO (or XENV)
> will be provided by Xen itself.
> Or, should we check STAO too?

Until we start seeing super-duper-visors Xen won't need to look for STAO.
Linux needs to look for STAO since it expects to potentially run under a
hypervisor, whereas Xen this isn't expected.

Graphics are a problem due to limits of ACPI table support.  Due to
graphics being a high priority for me, I'm temporarily using
device-trees.  :-(


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