[PATCH 1/2] DM_USB: allow building without OF_CONTROL

Simon Glass sjg at chromium.org
Sun Jun 27 21:06:12 CEST 2021


Hi Pali,

On Fri, 25 Jun 2021 at 10:58, Pali Rohár <pali at kernel.org> wrote:
>
> On Friday 25 June 2021 10:43:11 Simon Glass wrote:
> > Hi Pali,
> >
> > On Fri, 25 Jun 2021 at 10:16, Pali Rohár <pali at kernel.org> wrote:
> > >
> > > On Friday 25 June 2021 10:04:14 Simon Glass wrote:
> > > > But I do wonder about the
> > > > 100KB growth you saw with DT/DM. That seems absolutely enormous to me!
> > > > Can you please point me to the git tree for this? I'd like to
> > > > investigate.
> > >
> > > Patches in this series were written by Ivo. I do not know exact details
> > > and numbers. But the fact is that it was required to enable thumb-2 mode
> > > (which has hw bugs on this cpu, see earlier emails; reason why it was
> > > disabled). If you want to investigate it, you can try compare u-boot
> > > from master/next and u-boot with applying these patches + disable
> > > thumb-2 mode. Note that we have already enabled LTO.
> > >
> >
> > That's probably a little beyond my level of enthusiasm. But if you are
> > able to push a tree with before/after commits, I will take a look.
>
> Hello Simon! I have already pushed these patches to github due to CI
> testing. So you can easily access them via git fetch/checkout.
>
> Before (this is already in u-boot git):
> $ git checkout a298d4fbcdba1b38e48ea2af0fc5386cab2070da
>
> After1:
> $ git fetch https://github.com/u-boot/u-boot.git refs/pull/83/head
> $ git checkout 1f038c8b45ef0018e52a2a4587eb73170769ac2f
>
> After2:
> = use After1 with:
>   + disable CONFIG_SYS_THUMB_BUILD
>   + enable CONFIG_OF_LIBFDT_OVERLAY
>   + enable CONFIG_CMD_FDT
>
> defconfig file is nokia_rx51_defconfig

OK thanks, I see it. I pushed a tree to u-boot-dm/nokia_rx51 with a
few changes. The growth is about 19KB (without enabling Thumb). Some
more fine-grained control of what get enabled with LIBFDT could be
added to reduce that, perhaps by 5KB.

It has made me realise what a lot of bloat EBBR adds. I'll send a
patch to disable it by default.

Regards,
Simon


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