use invd instead of wbinvd in real mode start code

Andy Shevchenko
2020-02-17T14:00:40Z

On Mon, Feb 17, 2020 at 3:52 PM Bin Meng <bmeng.cn@gmail.com> wrote:
> On Mon, Feb 17, 2020 at 9:47 PM Andy Shevchenko
> <andy.shevchenko@gmail.com> wrote:
> > On Mon, Feb 17, 2020 at 3:39 PM Andy Shevchenko
> > <andy.shevchenko@gmail.com> wrote:
> > > On Mon, Feb 17, 2020 at 2:41 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
> > > > On Mon, Feb 17, 2020 at 9:31 PM Andy Shevchenko
> > > > <andy.shevchenko@gmail.com> wrote:

...

> > OK, as my intuition told me the problematic one is
> >
> > commit 0d67fac29f3187e67f4fd3ef15f73e91be2fad12
> > Author: Masahiro Yamada <masahiroy@kernel.org>
> > Date: Wed Jan 8 20:08:44 2020 +0900
> >
> > x86: use invd instead of wbinvd in real mode start code
> >
> >
> > Please, revert or fix ASAP before v2020.04 release!
> > ^^^
> >
> > > > > P.S. I dunno how it has been tested, so, if you have Intel Edison in
> > > > > possession, please, don't forget to test on it. It's not first time
> > > > > the Intel Edison behaviour is broken due to poor testing.
> > > >
> > > >
> > > > I tested my patches on qemu.
> > >
> > > Exactly my point of definition "poor".
> > > It's not first time (and not last) when QEmu sucks.
> > >
> > > > Sorry for the breakage on your board, but I do not
> > > > have Edison board.
> > > > It is not possible to test every board.
> > >
> > > No problem, it's rather to x86 maintainers to have at least one-two
> > > real hardware testing before applying this.
> > > QEMU is completely not enough!

> Is that because on Intel Edison U-Boot is not the first stage bootloader?

I don't know for sure, but I may speculate that this is a prerequisite.

--
With Best Regards,
Andy Shevchenko