[PATCH u-boot-marvell] PLEASE TEST ddr: marvell: a38x: fix SPLIT_OUT_MIX state decision

[Chris Packham]

On Mon, Jun 28, 2021 at 7:20 PM Pali Rohár <pali at kernel.org> wrote:
>
> On Monday 08 February 2021 21:24:09 Marek Behun wrote:
> > On Mon, 8 Feb 2021 20:14:26 +0000
> > Chris Packham <Chris.Packham at alliedtelesis.co.nz> wrote:
> >
> > > On 9/02/21 8:15 am, Marek Behun wrote:
> > > > This patch is needed on some Turris Omnia boards with Samsung DDR chips,
> > > > otherwise DDR training fails in ~60% of cases.
> > > >
> > > > Marvell send us this patch for testing, I have updated it a little.
> > > >
> > > > Please test this on other A38x boards.
> > > >
> > > > If it doesn't break anything on other boards, we can apply it and send
> > > > it to mv-ddr-marvell upstream.
> > > They gave us the same patch. I was hoping their SoC team would get it
> > > into mv-ddr-marvell (or even their vendor USP) but obviously they're
> > > still sitting on it. I know it improved matters for some of our boards
> > > but it didn't totally fix them we still had yield problems when we
> > > ramped up production.
> >
> > There is a bug in the version they sent us:
> >
> > in file ddr3_training_ip_engine.c there is a line added:
> >    if ((bit_bit_mask[sybphy_id] & (1 << bit_id)) == 1)
> >
> > try chaning it to
> >    if (bit_bit_mask[sybphy_id] & (1 << bit_id))
> >
> > This is fixed in the version I sent to mailing list
>
> Hello Chris! Have you tried above modification if it fixes your issue?

I haven't tried Marek's patch specifically. What we saw seemed to be a
yield issue rather than something that could be tested on just one
board. I must have missed Marek's response to my comment. Given that
he's identified at least one problem with Marvell's SPLIT_OUT_MIX
patch it's probably worth me trying it out on an x530 board. If that's
OK then I think U-Boot can take the patch (or even better
mv-ddr-marvell apply it and U-Boot syncs).