Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
IronPort-SDR: gcVkZ4H7bd9/yX6uMngufUGuDgYzV7vs4K0gtmF3VAGAb9RaNQrv7H/dNXUIqdP5fSC+FFMIzs
 Oo3FeiRbQhGQ==
IronPort-SDR: a3lIWqPE/g1jDM+p7cQw7M/N1Y/ingRLH9yG7WO64xsxvKNVSm2AqCOVr/J/nJGl1gUjdi9uiH
 dJxniEk8B1pg==
From:   "Liao, Bard" <bard.liao@intel.com>
To:     Vinod Koul <vkoul@kernel.org>,
        Bard Liao <yung-chuan.liao@linux.intel.com>
CC:     "alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "tiwai@suse.de" <tiwai@suse.de>,
        "broonie@kernel.org" <broonie@kernel.org>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "jank@cadence.com" <jank@cadence.com>,
        "srinivas.kandagatla@linaro.org" <srinivas.kandagatla@linaro.org>,
        "rander.wang@linux.intel.com" <rander.wang@linux.intel.com>,
        "ranjani.sridharan@linux.intel.com" 
        <ranjani.sridharan@linux.intel.com>,
        "hui.wang@canonical.com" <hui.wang@canonical.com>,
        "pierre-louis.bossart@linux.intel.com" 
        <pierre-louis.bossart@linux.intel.com>,
        "Kale, Sanyog R" <sanyog.r.kale@intel.com>,
        "Blauciak, Slawomir" <slawomir.blauciak@intel.com>,
        "Lin, Mengdong" <mengdong.lin@intel.com>
Subject: RE: [PATCH 3/3] soundwire: bus_type: add sdw_master_device support
Thread-Topic: [PATCH 3/3] soundwire: bus_type: add sdw_master_device support
Thread-Index: AQHWHrsvVp1w6XL6HkWXivkwcq57E6iifmqAgAAQ+dA=
Date:   Mon, 11 May 2020 08:04:43 +0000
Message-ID: <DM6PR11MB40748EA6346831A67BD218C7FFA10@DM6PR11MB4074.namprd11.prod.outlook.com>
References: <20200429185145.12891-1-yung-chuan.liao@linux.intel.com>
 <20200429185145.12891-4-yung-chuan.liao@linux.intel.com>
 <20200511063227.GS1375924@vkoul-mobl>
In-Reply-To: <20200511063227.GS1375924@vkoul-mobl>
Accept-Language: en-US
Content-Language: en-US
dlp-version: 11.2.0.6
dlp-reaction: no-action
dlp-product: dlpe-windows
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: efb13727-2230-4846-2aa3-08d7f581f705
X-MS-Exchange-CrossTenant-originalarrivaltime: 11 May 2020 08:04:43.9152
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 46c98d88-e344-4ed4-8496-4ed7712e255d
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: 83a6xzVVMCooAkJ86pZvbcTPyGTjsfRz6SR0G5HFHAXy9tNwPj/40BFImuibYXx10cRtyW9PPwlPlp0QJKGSrg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR11MB3818
X-OriginatorOrg: intel.com
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

> -----Original Message-----
> From: Vinod Koul <vkoul@kernel.org>
> Sent: Monday, May 11, 2020 2:32 PM
> To: Bard Liao <yung-chuan.liao@linux.intel.com>
> Cc: alsa-devel@alsa-project.org; linux-kernel@vger.kernel.org; tiwai@suse=
.de;
> broonie@kernel.org; gregkh@linuxfoundation.org; jank@cadence.com;
> srinivas.kandagatla@linaro.org; rander.wang@linux.intel.com;
> ranjani.sridharan@linux.intel.com; hui.wang@canonical.com; pierre-
> louis.bossart@linux.intel.com; Kale, Sanyog R <sanyog.r.kale@intel.com>;
> Blauciak, Slawomir <slawomir.blauciak@intel.com>; Lin, Mengdong
> <mengdong.lin@intel.com>; Liao, Bard <bard.liao@intel.com>
> Subject: Re: [PATCH 3/3] soundwire: bus_type: add sdw_master_device suppo=
rt
>=20
> On 30-04-20, 02:51, Bard Liao wrote:
> > @@ -24,9 +24,14 @@ int sdw_bus_master_add(struct sdw_bus *bus, struct
> device *parent,
> >  	struct sdw_master_prop *prop =3D NULL;
> >  	int ret;
> >
> > -	if (!bus->dev) {
> > -		pr_err("SoundWire bus has no device\n");
> > -		return -ENODEV;
>=20
> This check is removed and not moved into sdw_master_device_add() either, =
can
> you add here or in patch 1 and keep checking the parent device please

We will set bus->dev =3D &md->dev in the end of sdw_master_device_add().
That's why we remove the test. But now I am wandering does it make sense
to set bus->dev =3D &md->dev? Maybe it makes more sense to set bus->dev =3D
sdw control device.=20
A follow up question is that should slave device a child of bus device or
master device? I would prefer bus device if it makes sense.=20
I will check bus->dev and parent and remove bus->dev =3D &md->dev in the
next version.


>=20
> > +int sdw_master_device_add(struct sdw_bus *bus, struct device *parent,
> > +			  struct fwnode_handle *fwnode)
> > +{
> > +	struct sdw_master_device *md;
> > +	int ret;
> > +
> > +	if (!bus)
> > +		return -EINVAL;
> > +
> > +	/*
> > +	 * Unlike traditional devices, there's no allocation here since the
> > +	 * sdw_master_device is embedded in the bus structure.
> > +	 */
>=20
> Looking at this and empty sdw_master_device_release() above, makes me
> wonder if it is a wise move? Should we rather allocate the
> sdw_master_device() and then free that up in sdw_master_device_release() =
or it
> is really overkill given that this is called when we remove the sdw_bus i=
nstance
> as well...

Yes, I will allocate sdw_master_device here and free it in
sdw_master_device_release().

>=20
> > +	md =3D &bus->md;
> > +	md->dev.bus =3D &sdw_bus_type;
> > +	md->dev.type =3D &sdw_master_type;
> > +	md->dev.parent =3D parent;
> > +	md->dev.of_node =3D parent->of_node;
> > +	md->dev.fwnode =3D fwnode;
> > +	md->dev.dma_mask =3D parent->dma_mask;
> > +
> > +	dev_set_name(&md->dev, "sdw-master-%d", bus->link_id);
>=20
> This give nice sdw-master-0. In DT this comes from reg property. I dont s=
eem to
> recall if the ACPI/Disco spec treats link_id as unique across the system,=
 can you
> check that please, if not we would need to update this.

Sure, I will check it.

>=20
> --
> ~Vinod