Date: Thu, 27 Oct 2022 15:42:52 +0100 From: void <void@f-m.fm> To: freebsd-current@freebsd.org Subject: Re: ns8250: UART FCR is broken Message-ID: <Y1qY7ACJwwkb4PqH@openbsd.local> In-Reply-To: <fa45b3cc-fa65-b5b9-49fa-a1dcbbddebc6@freebsd.org> References: <Y1dF0CvrJZubFizl@openbsd.local> <CAPyFy2CeWi2_ejv6%2BdKQB6Sa0KLpe0Kq8=p4QNS46HDkADCB9Q@mail.gmail.com> <fa45b3cc-fa65-b5b9-49fa-a1dcbbddebc6@freebsd.org>
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On Wed, Oct 26, 2022 at 02:15:29PM -0700, Colin Percival wrote:
>Indeed, looking at usr.sbin/bhyve/uart_emul.c it looks like FCR_XMT_RST is
>not emulated. This is different from Firecracker, which doesn't emulate
>either anything from the FCR and where I was seeing the receive side not
>being flushed, but I'm glad my warning was able to flag a bug. :-)
>
>If "void" is comfortable with kernel hacking, it would be great to confirm
>that the warning is indeed coming from the transmit side not being flushed;
>a printf("drain = %d\n", drain); would be sufficient.
>
>And yes, only emitting this warning once per device (or once per boot?)
>would probably be good.
I'm happy to do some kernel hacking with this vm. Tell me what I need to
do.
Thanks,
--
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