[U-Boot] [PATCH v2 1/4] ns16550: Add function to drain serial output

Simon Glass sjg at chromium.org
Fri Mar 9 22:29:16 CET 2012

Hi Stephen,

On Fri, Mar 9, 2012 at 1:23 PM, Tom Warren <TWarren at nvidia.com> wrote:
> Simon/Stephen,
>> -----Original Message-----
>> From: sjg at google.com [mailto:sjg at google.com] On Behalf Of Simon Glass
>> Sent: Friday, March 09, 2012 2:09 PM
>> To: Stephen Warren
>> Cc: U-Boot Mailing List; Tom Warren
>> Subject: Re: [PATCH v2 1/4] ns16550: Add function to drain serial output
>> Hi,
>> On Fri, Mar 9, 2012 at 1:00 PM, Stephen Warren <swarren at wwwdotorg.org>
>> wrote:
>> > On 03/09/2012 01:32 PM, Simon Glass wrote:
>> >> Sometimes we want to be sure that the output FIFO has fully drained (e.g.
>> >> because we are about to reset or the port or reset the board). Add a
>> >> function for this.
>> >>
>> >> Signed-off-by: Simon Glass <sjg at chromium.org>
>> >
>> > The series,
>> >
>> > Tested-by: Stephen Warren <swarren at wwwdotorg.org>
>> >
>> > Tom,
>> >
>> > I'm OK with you adding these patches to u-boot-tegra/master and
>> > sending a pull request for that. Just please put these patches before
>> > any that actually enable CONFIG_OF_CONTROL for any boards, so there's
>> > never a window of broken commits.
>> >
>> > I think it'd be nice at this stage to also drop the commit that turns
>> > Ventana into a DT board, since re-using the Seaboard .dts file for
>> > Ventana isn't correct. However, IIRC that commit was added to WAR some
>> > build issue with Simon's patch series? If that's still a problem, then
>> > I'm OK with converting Ventana if we have to, but we'll need to be
>> > very careful that tegra-seaboard.dts doesn't add stuff that'll fail
>> > on, or damage, Ventana.
>> A few points:
>> 1. Yes you can drop the Ventana commit and I agree it is a good idea.
>> We should have a real Ventana .dts file I think. Ventana should built ok
>> without a device tree now. The problem was in my clock.c patch.
>> 2. I have held off responding to Stephen's patch on the ML to see what other
>> say. My view is that it is controversial since it changes the so-far
>> accepted meaning of u-boot.bin and the behaviour of the U-Boot Makefile.
>> Plus it is not really necessary as a means of informing the user since we
>> put the pre-console putc() for exactly this problem. So I would rather leave
>> Stephen's patch out at until people have time to decide that I am wrong
>> about it. We already have CONFIG_OF_EMBED to build the fdt into u-boot.bin.
>> Grant Likely had big reservations about this feature - let's not bring it in
>> by stealth.
> I see now why it's so hard to find custodians for the U-Boot repos. :/
> I've done as Stephen requested and re-ordered the commits so his Makefile fix comes before the config file changes to add CONFIG_OF_CONTROL to Seaboard and Ventana.
> I've left the Ventana change that uses the Seaboard .dts file in, as I think it can easily be edited to use a Ventana-specific dts file just as soon as one of you finds one and submits a patch for it. For now, the Seaboard .dts just works.
> I've pushed my latest changes to u-boot-tegra/master, and I'm going to let it percolate over the weekend. I'd have liked to get a pull request in to Albert today, before the ARM HEAD moves again, but I'm not going sweat to it since there doesn't seem to be a consensus on how to proceed here. IMO, I see no problem with putting these patches in as they stand, since I've tested them to work OK on Seaboard and Ventana, other (non-DT) Tegra2 boards build fine, and anything here that needs to change can always be edited with a future patch. But I'm going to head out early (it's my birthday today), and pick this up again next week.

Happy Birthday Tom!

Stephen, what you do you about leaving out your Makefile patch for
now? It is (I think) the only controversial part of this, and is not
needed to make all this work...


> Tom
> --
> nvpublic
>> Regards,
>> Simon

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