Re: ns8250: UART FCR is broken

Reply: Colin Percival : "Re: ns8250: UART FCR is broken"
In reply to: void : "ns8250: UART FCR is broken"
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From: Ed Maste <emaste_at_freebsd.org>
Date: Wed, 26 Oct 2022 20:48:11 UTC

On Mon, 24 Oct 2022 at 22:11, void <void@f-m.fm> wrote:
>
> hello freebsd-current@,
>
> this started appearing in dmesg
>
> ns8250: UART FCR is broken
> ns8250: UART FCR is broken

This message was added as part of Colin's work to support FreeBSD in
the Firecracker VMM
https://cgit.freebsd.org/src/commit/?id=c4b68e7e53bb352be3fa16995b99764c03097e66

In this case it indicates that bhyve has the same bug/missing
functionality as Firecracker -- it doesn't implement the FCR_XMT_RST
or FCR_RCV_RST bits. You can safely ignore the message, and it will
disappear once someone adds the required support to bhyve. We should
probably also have the kernel emit the message only once. I've CC'd
Colin for comment.