[PATCH 007/108] dm: pci: Allow disabling auto-config for a device

[Bin Meng]

Hi Simon,

On Sun, Feb 9, 2020 at 12:07 AM Simon Glass <sjg at chromium.org> wrote:
>
> Hi Bin,
>
> On Sat, 8 Feb 2020 at 08:54, Bin Meng <bmeng.cn at gmail.com> wrote:
> >
> > Hi Simon,
> >
> > On Sat, Feb 8, 2020 at 11:51 PM Simon Glass <sjg at chromium.org> wrote:
> > >
> > > Hi Bin,
> > >
> > > On Sat, 8 Feb 2020 at 08:15, Bin Meng <bmeng.cn at gmail.com> wrote:
> > > >
> > > > Hi Simon,
> > > >
> > > > On Mon, Jan 27, 2020 at 1:08 PM Simon Glass <sjg at chromium.org> wrote:
> > > > >
> > > > > Add a means to avoid configuring a device when needed. Add an explanation
> > > > > of why this is useful to the binding file.
> > > > >
> > > >
> > > > Does disabling CONFIG_PCI_PNP not help?
> > >
> > > That is for all devices. Here we just want the UART to stay where it
> > > is so that we can debug serial drivers, FSP-S, etc. If the UART moves
> > > then any output after that hangs the machine until we reinit the
> > > serial driver.
> >
> > OK, I think this is for debugging purpose, right? As you must have get
> > Coral boot for some time, and this is only for retaining the console
> > debug output?
>
> Sort-of, but I've actually left it enabled. The problem is that if you
> get an error or any debug output very early after relocation in
> U-Boot, it hangs. I feel it is quite confusing for people to add a bit
> of debugging and have it crash.
>
> Admittedly there is a very small window where this happens (roughly
> between arch_fsp_init_r() returning and initr_serial() being called.
> But i found it pretty annoying.
>
> What do you think?
>

Sounds good to me for leaving it enabled by default.

> Also I'd like to change it to suppress console output when it is not
> allowed (and print a warning later), but haven't tried that yet.
>

Regards,
Bin