Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B931D21749
Date:   Thu, 22 Mar 2018 00:11:56 +0000
From:   James Hogan <jhogan@kernel.org>
To:     NeilBrown <neil@brown.name>
Cc:     John Crispin <john@phrozen.org>,
        Ralf Baechle <ralf@linux-mips.org>, linux-mips@linux-mips.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] MIPS: ralink: fix booting on mt7621
Message-ID: <20180322001155.GD13126@saruman>
References: <87efkf9z0o.fsf@notabene.neil.brown.name>
 <87605r9mwf.fsf@notabene.neil.brown.name>
 <871sge872l.fsf@notabene.neil.brown.name>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha256;
        protocol="application/pgp-signature"; boundary="PHCdUe6m4AxPMzOu"
Content-Disposition: inline
In-Reply-To: <871sge872l.fsf@notabene.neil.brown.name>
User-Agent: Mutt/1.7.2 (2016-11-26)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


--PHCdUe6m4AxPMzOu
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Wed, Mar 21, 2018 at 02:02:10PM +1100, NeilBrown wrote:
>=20
> Since commit 3af5a67c86a3 ("MIPS: Fix early CM probing") the MT7621
> has not been able to boot.
>=20
> This patched caused mips_cm_probe() to be called before
> mt7621.c::proc_soc_init().
>=20
> prom_soc_init() has a comment explaining that mips_cm_probe()
> "wipes out the bootloader config" and means that configuration
> registers are no longer available.  It has some code to re-enable
> this config.
>=20
> Before this re-enable code is run, the sysc register cannot be
> read, so when SYSC_REG_CHIP_NAME0 is read, a garbage value
> is returned and panic() is called.
>=20
> If we move the config-repair code to the top of prom_soc_init(),
> the registers can be read and boot can proceed.
>=20
> Very occasionally, the first register read after the reconfiguration
> returns garbage.  So I added a call to __sync().
>=20
> Fixes: 3af5a67c86a3 ("MIPS: Fix early CM probing")
> Signed-off-by: NeilBrown <neil@brown.name>

Looks good. I've cosmetically tweaked commit message (mainly reflow),
added stable tag for 4.5+, and applied for 4.16.

Thanks
James

--PHCdUe6m4AxPMzOu
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: Digital signature

-----BEGIN PGP SIGNATURE-----
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=c5hx
-----END PGP SIGNATURE-----

--PHCdUe6m4AxPMzOu--