Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Mon, 3 Apr 2023 22:12:44 +0100
From:   Mark Brown <broonie@kernel.org>
To:     William Breathitt Gray <william.gray@linaro.org>
Cc:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Linus Walleij <linus.walleij@linaro.org>,
        Bartosz Golaszewski <brgl@bgdev.pl>,
        linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org,
        techsupport@winsystems.com,
        Paul Demetrotion <pdemetrotion@winsystems.com>,
        Michael Walle <michael@walle.cc>
Subject: Re: [PATCH v5 3/3] gpio: ws16c48: Migrate to the regmap API
Message-ID: <f4377c61-8745-477d-ab8f-f83de203c4b3@sirena.org.uk>
References: <cover.1679845842.git.william.gray@linaro.org>
 <58531b1b2428e4d5d2ea79e721f7ef6450665280.1679845842.git.william.gray@linaro.org>
 <ZCF9bdyefA/oDmdG@smile.fi.intel.com>
 <ZCmThuzUBYdp29UR@fedora>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
        protocol="application/pgp-signature"; boundary="bT3UYpp4c8gGNugV"
Content-Disposition: inline
In-Reply-To: <ZCmThuzUBYdp29UR@fedora>
Precedence: bulk


--bT3UYpp4c8gGNugV
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

On Sun, Apr 02, 2023 at 10:39:02AM -0400, William Breathitt Gray wrote:
> On Mon, Mar 27, 2023 at 02:26:37PM +0300, Andy Shevchenko wrote:
> > On Sun, Mar 26, 2023 at 12:25:59PM -0400, William Breathitt Gray wrote:

> > > +static const struct regmap_config ws16c48_regmap_config = {
> > > +	.reg_bits = 8,
> > > +	.reg_stride = 1,
> > > +	.val_bits = 8,
> > > +	.io_port = true,
> > > +	.max_register = 0xA,
> > > +	.wr_table = &ws16c48_wr_table,
> > > +	.rd_table = &ws16c48_rd_table,
> > > +	.volatile_table = &ws16c48_volatile_table,
> > > +	.cache_type = REGCACHE_FLAT,
> > > +};

> > Do we need regmap lock?

> We make regmap calls within an interrupt context in this driver so I
> think we need to disable the default regmap mutex locking behavior; I
> believe the current raw_spin_lock locking in this driver is enough to
> protect access.

The above doesn't configure the regmap locking so you'll have a spinlock
by default (MMIO being a fast bus).

--bT3UYpp4c8gGNugV
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----

iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmQrQUsACgkQJNaLcl1U
h9CqqAf9FQjwis8MhjhP8nggcH+Uy1nBfbCZAZoBxcGt2KoVGlL02rn1j2xZvRq+
cDL4HypzWQ0kPMWd7emRcoerwa6YkDrvj3B3bC9zY1Gg+wjYWqe+EcFlMRRxbp6o
ZKa8ef0vj1Yk3aq54rHzXZf+2t5rxTe8bF84hDV2eq4lTbYQUGxCWh0Vf/yQkrBw
LAYJ1MoboaBVmerUKDuBmpZZeK6EjOVKPj4NK7XUOnAXtTEKms9w6jdzzi+FPjmm
ewdoceQ25lFQDwLJqMBvi2rFBlb5PChR1lxbL8JHp6M3TB4F5f8TQH/LY+hi50Ye
LgmaVHQSyamtrvPgChs/q/n6wZsqvg==
=zgHq
-----END PGP SIGNATURE-----

--bT3UYpp4c8gGNugV--