[PATCH 5/9] fdt: Correct condition for bloblist existing

[Simon Glass]

Hi all,

On Fri, 21 Jun 2024 at 12:16, Simon Glass <sjg at chromium.org> wrote:
>
> Hi Raymond,
>
> On Fri, 21 Jun 2024 at 10:40, Raymond Mao <raymond.mao at linaro.org> wrote:
> >
> > Hi Simon,
> >
> > On Fri, 21 Jun 2024 at 10:58, Simon Glass <sjg at chromium.org> wrote:
> >>
> >> Hi Ilias,
> >>
> >> On Wed, 19 Jun 2024 at 06:41, Ilias Apalodimas
> >> <ilias.apalodimas at linaro.org> wrote:
> >> >
> >> > Hi Simon,
> >> >
> >> > On Wed, Jun 12, 2024 at 02:24:31PM -0600, Simon Glass wrote:
> >> > > Hi Ilias,
> >> > >
> >> > > On Wed, 12 Jun 2024 at 00:02, Ilias Apalodimas
> >> > > <ilias.apalodimas at linaro.org> wrote:
> >> > > >
> >> > > > [...]
> >> > > >
> >> > > > > > > >> ---
> >> > > > > > > >>
> >> > > > > > > >>  lib/fdtdec.c | 12 ++++++++++--
> >> > > > > > > >>  1 file changed, 10 insertions(+), 2 deletions(-)
> >> > > > > > > >>
> >> > > > > > > >> diff --git a/lib/fdtdec.c b/lib/fdtdec.c
> >> > > > > > > >> index b2c59ab3818..b141244e3b9 100644
> >> > > > > > > >> --- a/lib/fdtdec.c
> >> > > > > > > >> +++ b/lib/fdtdec.c
> >> > > > > > > >> @@ -1669,8 +1669,16 @@ int fdtdec_setup(void)
> >> > > > > > > >>  {
> >> > > > > > > >>         int ret = -ENOENT;
> >> > > > > > > >>
> >> > > > > > > >> -       /* If allowing a bloblist, check that first */
> >> > > > > > > >> -       if (CONFIG_IS_ENABLED(BLOBLIST)) {
> >> > > > > > > >> +       /*
> >> > > > > > > >> +        * If allowing a bloblist, check that first. This would be better
> >> > > > > > > >> +        * handled with an OF_BLOBLIST Kconfig, but that caused far too much
> >> > > > > > > >> +        * argument, so add a hack here, used e.g. by chromebook_coral
> >> > > > > > > >
> >> > > > > > > > I am a bit confused by this comment - It means you will not use OF_BLOBLIST,
> >> > > > > > > > but actually you are using it below. Is it a typo?
> >> > > > > > >
> >> > > > > > > Basically it would be cleaner to have a separate, phase-specific
> >> > > > > > > Kconfig control as to whether the DT can come from the bloblist (I
> >> > > > > > > can't remember the Kconfig name I suggested, nor the patch as it was
> >> > > > > > > last year sometime). But for now I am adding this hack to get a few
> >> > > > > > > boards working again.
> >> > > > > >
> >> > > > > > I am a bit confused.
> >> > > > > > First of all the comment is innapropriate. We went through a lengthy
> >> > > > > > discussion on BLOBLIST/OF_BLOSLIST etc and,  even Tom chimed in and we
> >> > > > > > made up our minds. Why are you adding this comment now? Why do code
> >> > > > > > comments have to illustrate your personal opinion -- which was
> >> > > > > > rejected?
> >> > > > >
> >> > > > > I'm sorry for the tone of the comment. I am not trying to offend
> >> > > > > anyone here and I'm happy to change the language.
> >> > > >
> >> > > > Yes please a comment explaining why that piece of code is there is far
> >> > > > more intuitive.
> >> > >
> >> > > OK, once we have agreed the below I can do that.
> >> > >
> >> > > >
> >> > > > >  As I probably
> >> > > > > mentioned at the time, my accepted patch breaks my workflow and
> >> > > > > several boards. I hope you can understand how frustrating that sort of
> >> > > > > thing can be.
> >> > > >
> >> > > > Yes, I do and I am fine with a short-term patch that fixes issues, as
> >> > > > long as its not too intrusive. There is a very thin line between quick
> >> > > > and dirty fixes to spaghetti unreadable code. But we should have
> >> > > > comments and/or commit messages indicating that this needs a proper
> >> > > > fix
> >> > >
> >> > > I spent a lot of time explaining this last time.
> >> > >
> >> > > >
> >> > > > > Also, now that I have my lab back up and running and I
> >> > > > > would like these boards to work again on mainline!
> >> > > > >
> >> > > > > >
> >> > > > > > Grepping for OF_BLOBLIST, I can't find any matches, so is the above if a typo?
> >> > > > >
> >> > > > > Remember, it was a patch you rejected :-)
> >> > > >
> >> > > > I don't maintain any of that. I only gave some feedback along the
> >> > > > lines of "bloblist was designed to be auto-discoverable, I don't see
> >> > > > how adding an explicit Kconfig helps". IIRC we eventually followed
> >> > > > what Tom suggested.
> >> > >
> >> > > I'm not trying to point the finger here. So far the boards are broken
> >> > > in mainline...I'm just trying to fix that,
> >> > >
> >> > > >
> >> > > > In any case, the amount of bike-shedding in the topic is too much. Do
> >> > > > you mind explaining the problem in your workflow again? Perhaps we can
> >> > > > find a solution that is integrated in bloblist_maybe_init() instead of
> >> > > > injecting ifs on when a bloblist should or should not be searched for
> >> > > > all over the place.
> >> > >
> >> > > TPL (or SPL) sets up a bloblist with bits of info in it, but no DT
> >> > > (which is in memory-mapped SPI flash)
> >> > > U-Boot proper starts up, it wants to get the bloblist but not hang if
> >> > > the bloblist doesn't have a DT
> >> >
> >> > Sure, that's reasonable and IIRC that's the design we agreed a while back.
> >> > Looking at the code, if the DT isn't found in a bloblist and the feature is
> >> > enabled, we don't crash. We just print a debug message and continue to find
> >> > the DT as we used. Why do we have to skip the call to
> >> > bloblist_maybe_init()?
> >>
> >> Because at this point, if there is no bloblist, then it needs to be
> >> created. But creating it this early may fail, e.g. since there is no
> >> malloc(). The intent of this code is to locate an FDT from an existing
> >> bloblist. There is no point in creating a new bloblist here, since it
> >> obviously won't have an FDT in it.
> >>
> > Can we add a bool arg to bloblist_init for this?
> > Eg. int bloblist_init(bool allow_malloc);
>
> Yes, we can do anything, but that seems like a hack to me...if we init
> the bloblist for the first time in the current phase, then it
> obviously won't have an FDT inside it. It is the unconditional
> requirement of an FDT which is causing the problems here.

Can we apply this patch, please? I still have several broken boards in
my lab due to this.

Regards,
Simon