Re: [PATCH v2 1/4] tty: serial: Add 8250 earlycon to support noinit option

From: Alan Cox
Date: Mon Jan 12 2015 - 11:09:39 EST


On Mon, 2015-01-12 at 16:35 +0100, Arnd Bergmann wrote:
> On Monday 12 January 2015 21:08:21 Eddie Huang wrote:
> > Add earlycon support not only baudrate option, but also add noinit option.
> > If use noinit option, 8250 earlycon will not init serial hardware and use
> > loader setting.
> >
> > Signed-off-by: Eddie Huang <eddie.huang@xxxxxxxxxxxx>
>
> I probably missed something in the previous discussion, but why is
> "noinit" not just the default? I believe that is how we handle early
> serial ports on PowerPC, and I see no downsides to it.

Most PC hardware at least needs the port initialised to use it. It won't
have been configured by the firmware in many cases.

Alan


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