Re: [PATCH] riscv: Fix 32-bit RISC-V boot failure

[Palmer Dabbelt]

On Thu, 15 Jul 2021 19:14:20 PDT (-0700), bmeng.cn@xxxxxxxxx wrote:
> On Thu, Jul 8, 2021 at 9:29 PM Bin Meng <bmeng.cn@xxxxxxxxx> wrote:
> > Hi Palmer,
> >
> > On Thu, Jul 1, 2021 at 10:20 AM Bin Meng <bmeng.cn@xxxxxxxxx> wrote:
> > >
> > > On Thu, Jul 1, 2021 at 10:08 AM Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote:
> > > >
> > > >
> > > > On 2021/6/30 19:58, Bin Meng wrote:
> > > > > On Mon, Jun 28, 2021 at 11:21 AM Bin Meng <bmeng.cn@xxxxxxxxx> wrote:
> > > > >> On Mon, Jun 28, 2021 at 10:28 AM Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote:
> > > > >>>
> > > > >>> On 2021/6/28 9:15, Bin Meng wrote:
> > > > >>>> On Mon, Jun 28, 2021 at 8:53 AM Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote:
> > > > >>>>> Hi， sorry for the mistake，the bug is fixed by
> > > > >>>>>
> > > > >>>>> https://lore.kernel.org/linux-riscv/20210602085517.127481-2-wangkefeng.wang@xxxxxxxxxx/
> > > > >>>> What are we on the patch you mentioned?
> > > > >>>>
> > > > >>>> I don't see it applied in the linux/master.
> > > > >>>>
> > > > >>>> Also there should be a "Fixes" tag and stable@xxxxxxxxxxxxxxx cc'ed
> > > > >>>> because 32-bit is broken since v5.12.
> > > > >>> https://kernel.googlesource.com/pub/scm/linux/kernel/git/riscv/linux/+/c9811e379b211c67ba29fb09d6f644dd44cfcff2
> > > > >>>
> > > > >>> it's on Palmer' riscv-next.
> > > > >> Not sure riscv-next is for which release? This is a regression and
> > > > >> should be on 5.13.
> > > > >>
> > > > >>> Hi Palmer, should I resend or could you help me to add the fixes tag?
> > > > > Your patch mixed 2 things (fix plus one feature) together, so it is
> > > > > not proper to back port your patch.
> > > >
> > > > "mem=" will change the range of memblock, so the fix part must be included.
> > > >
> > >
> > > Yes, so you can rebase the "mem=" changes on top of my patch.
> > >
> > > The practice is that we should not mix 2 things in one patch. I can
> > > imagine that you wanted to add "mem=" to RISC-V and suddenly found the
> > > existing logic was broken, so you sent one patch to do both.
> > >
> > > >
> > > > >
> > > > > Here is my 2 cents:
> > > > >
> > > > > 1. Drop your patch from riscv-next
> > > > > 2. Apply my patch as it is a simple fix to previous commit. This
> > > > > allows stable kernel to cherry-pick the fix to v5.12 and v5.13.
> > > > > 3. Rebase your patch against mine, and resend v2
> > > > >
> > > > > Let me know if this makes sense.
> > > >
> > > > It is not a big problem for me, but I have no right abourt riscv-next,
> > > >
> > > > let's wait Palmer's advise.
> > > >
> > >
> > > Sure. Palmer, let me know your thoughts.
> >
> > Ping?
>
> Ping?

Sorry, I missed this one.  It looks like the patch that adds mem= and 
fixes the bug has already been merged, so I'm not really quite sure what 
the right thing to do is here: we don't really want the mem= code on 
stable, but we do want the fix.  I went ahead and did

commit 444818b599189fd8b6c814da542ff8cfc9fe67d4 (HEAD -> fixes, palmer/fixes)
gpg: Signature made Wed 21 Jul 2021 10:21:05 PM PDT
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gpg: Good signature from "Palmer Dabbelt <palmer@xxxxxxxxxxx>" [ultimate]
gpg:                 aka "Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>" [ultimate]
Merge: e73f0f0ee754 d0e4dae74470
Author: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
Date:   Wed Jul 21 22:18:58 2021 -0700

   Merge remote-tracking branch 'riscv/riscv-fix-32bit' into fixes

   This contains a single fix for 32-bit boot.  It happens this was already
   fixed by c9811e379b21 ("riscv: Add mem kernel parameter support"), but
   the bug existed before that feature addition so I've applied the patch
   earlier and then merged it in (which results in a conflict, which is
   fixed via not changing the resulting tree).

   * riscv/riscv-fix-32bit:
     riscv: Fix 32-bit RISC-V boot failure

as that"s the best I could come up with -- then the fix will land on 
master, which should cause it to get pulled onto stable.

Greg: is there a better way to make something like this get to stable?