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Date:   Thu, 8 Aug 2019 19:04:34 +0300
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Wolfram Sang <wsa@the-dreams.de>
Cc:     Kieran Bingham <kieran.bingham@ideasonboard.com>,
        Wolfram Sang <wsa+renesas@sang-engineering.com>,
        linux-i2c@vger.kernel.org, Andrzej Hajda <a.hajda@samsung.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        linux-media@vger.kernel.org
Subject: Re: [PATCH] i2c: replace i2c_new_secondary_device with an ERR_PTR
 variant
Message-ID: <20190808160434.GT6055@pendragon.ideasonboard.com>
References: <20190722172600.3452-1-wsa+renesas@sang-engineering.com>
 <9b71c556-bd70-4d29-dba5-fbeaefb5f3b4@ideasonboard.com>
 <20190808155709.GA1316@ninjato>
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On Thu, Aug 08, 2019 at 05:57:09PM +0200, Wolfram Sang wrote:
> On Tue, Jul 23, 2019 at 04:47:09PM +0100, Kieran Bingham wrote:
> > On 22/07/2019 18:26, Wolfram Sang wrote:
> > > In the general move to have i2c_new_*_device functions which return
> > > ERR_PTR instead of NULL, this patch converts i2c_new_secondary_device().
> > > 
> > > There are only few users, so this patch converts the I2C core and all
> > > users in one go. The function gets renamed to i2c_new_ancillary_device()
> > > so out-of-tree users will get a build failure to understand they need to
> > > adapt their error checking code.
> > > 
> > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> > > ---
> > > 
> > > Kindly asking for acks/revs/tests from people knowing the modified
> > > drivers.
> > 
> > Certainly, this looks good for the adv748x.
> > 
> > The ADV7511, and adv7604 are not mine, but they also look fine to me.
> > 
> > Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> 
> Thanks, Kieran! Gently pinging for acks for ADV7511 and ADV7604.

For the adv7511 driver,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

For the adv7604 driver, please see below.

> > >  drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 18 +++++++++---------
> > >  drivers/i2c/i2c-core-base.c                  | 10 +++++-----
> > >  drivers/media/i2c/adv748x/adv748x-core.c     |  6 +++---
> > >  drivers/media/i2c/adv7604.c                  | 10 +++++-----
> > >  include/linux/i2c.h                          |  2 +-
> > >  5 files changed, 23 insertions(+), 23 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > > index f6d2681f6927..9e13e466e72c 100644
> > > --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > > +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > > @@ -981,10 +981,10 @@ static int adv7511_init_cec_regmap(struct adv7511 *adv)
> > >  {
> > >  	int ret;
> > >  
> > > -	adv->i2c_cec = i2c_new_secondary_device(adv->i2c_main, "cec",
> > > +	adv->i2c_cec = i2c_new_ancillary_device(adv->i2c_main, "cec",
> > >  						ADV7511_CEC_I2C_ADDR_DEFAULT);
> > > -	if (!adv->i2c_cec)
> > > -		return -EINVAL;
> > > +	if (IS_ERR(adv->i2c_cec))
> > > +		return PTR_ERR(adv->i2c_cec);
> > >  	i2c_set_clientdata(adv->i2c_cec, adv);
> > >  
> > >  	adv->regmap_cec = devm_regmap_init_i2c(adv->i2c_cec,
> > > @@ -1165,20 +1165,20 @@ static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
> > >  
> > >  	adv7511_packet_disable(adv7511, 0xffff);
> > >  
> > > -	adv7511->i2c_edid = i2c_new_secondary_device(i2c, "edid",
> > > +	adv7511->i2c_edid = i2c_new_ancillary_device(i2c, "edid",
> > >  					ADV7511_EDID_I2C_ADDR_DEFAULT);
> > > -	if (!adv7511->i2c_edid) {
> > > -		ret = -EINVAL;
> > > +	if (IS_ERR(adv7511->i2c_edid)) {
> > > +		ret = PTR_ERR(adv7511->i2c_edid);
> > >  		goto uninit_regulators;
> > >  	}
> > >  
> > >  	regmap_write(adv7511->regmap, ADV7511_REG_EDID_I2C_ADDR,
> > >  		     adv7511->i2c_edid->addr << 1);
> > >  
> > > -	adv7511->i2c_packet = i2c_new_secondary_device(i2c, "packet",
> > > +	adv7511->i2c_packet = i2c_new_ancillary_device(i2c, "packet",
> > >  					ADV7511_PACKET_I2C_ADDR_DEFAULT);
> > > -	if (!adv7511->i2c_packet) {
> > > -		ret = -EINVAL;
> > > +	if (IS_ERR(adv7511->i2c_packet)) {
> > > +		ret = PTR_ERR(adv7511->i2c_packet);
> > >  		goto err_i2c_unregister_edid;
> > >  	}
> > >  
> > > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> > > index f26ed495d384..76cb91e064b8 100644
> > > --- a/drivers/i2c/i2c-core-base.c
> > > +++ b/drivers/i2c/i2c-core-base.c
> > > @@ -966,7 +966,7 @@ struct i2c_client *devm_i2c_new_dummy_device(struct device *dev,
> > >  EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device);
> > >  
> > >  /**
> > > - * i2c_new_secondary_device - Helper to get the instantiated secondary address
> > > + * i2c_new_ancillary_device - Helper to get the instantiated secondary address
> > >   * and create the associated device
> > >   * @client: Handle to the primary client
> > >   * @name: Handle to specify which secondary address to get
> > > @@ -985,9 +985,9 @@ EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device);
> > >   * cell whose "reg-names" value matches the slave name.
> > >   *
> > >   * This returns the new i2c client, which should be saved for later use with
> > > - * i2c_unregister_device(); or NULL to indicate an error.
> > > + * i2c_unregister_device(); or an ERR_PTR to describe the error.
> > >   */
> > > -struct i2c_client *i2c_new_secondary_device(struct i2c_client *client,
> > > +struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client,
> > >  						const char *name,
> > >  						u16 default_addr)
> > >  {
> > > @@ -1002,9 +1002,9 @@ struct i2c_client *i2c_new_secondary_device(struct i2c_client *client,
> > >  	}
> > >  
> > >  	dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr);
> > > -	return i2c_new_dummy(client->adapter, addr);
> > > +	return i2c_new_dummy_device(client->adapter, addr);
> > >  }
> > > -EXPORT_SYMBOL_GPL(i2c_new_secondary_device);
> > > +EXPORT_SYMBOL_GPL(i2c_new_ancillary_device);
> > >  
> > >  /* ------------------------------------------------------------------------- */
> > >  
> > > diff --git a/drivers/media/i2c/adv748x/adv748x-core.c b/drivers/media/i2c/adv748x/adv748x-core.c
> > > index f57cd77a32fa..2567de2b0037 100644
> > > --- a/drivers/media/i2c/adv748x/adv748x-core.c
> > > +++ b/drivers/media/i2c/adv748x/adv748x-core.c
> > > @@ -183,14 +183,14 @@ static int adv748x_initialise_clients(struct adv748x_state *state)
> > >  	int ret;
> > >  
> > >  	for (i = ADV748X_PAGE_DPLL; i < ADV748X_PAGE_MAX; ++i) {
> > > -		state->i2c_clients[i] = i2c_new_secondary_device(
> > > +		state->i2c_clients[i] = i2c_new_ancillary_device(
> > >  				state->client,
> > >  				adv748x_default_addresses[i].name,
> > >  				adv748x_default_addresses[i].default_addr);
> > >  
> > > -		if (state->i2c_clients[i] == NULL) {
> > > +		if (IS_ERR(state->i2c_clients[i])) {
> > >  			adv_err(state, "failed to create i2c client %u\n", i);
> > > -			return -ENOMEM;
> > > +			return PTR_ERR(state->i2c_clients[i]);
> > >  		}
> > >  
> > >  		ret = adv748x_configure_regmap(state, i);
> > > diff --git a/drivers/media/i2c/adv7604.c b/drivers/media/i2c/adv7604.c
> > > index 28a84bf9f8a9..8ed1d9b59dd2 100644
> > > --- a/drivers/media/i2c/adv7604.c
> > > +++ b/drivers/media/i2c/adv7604.c
> > > @@ -2878,14 +2878,14 @@ static struct i2c_client *adv76xx_dummy_client(struct v4l2_subdev *sd,
> > >  	struct i2c_client *new_client;
> > >  
> > >  	if (pdata && pdata->i2c_addresses[page])
> > > -		new_client = i2c_new_dummy(client->adapter,
> > > +		new_client = i2c_new_dummy_device(client->adapter,
> > >  					   pdata->i2c_addresses[page]);
> > >  	else
> > > -		new_client = i2c_new_secondary_device(client,
> > > +		new_client = i2c_new_ancillary_device(client,
> > >  				adv76xx_default_addresses[page].name,
> > >  				adv76xx_default_addresses[page].default_addr);
> > >  
> > > -	if (new_client)
> > > +	if (!IS_ERR(new_client))
> > >  		io_write(sd, io_reg, new_client->addr << 1);
> > >  
> > >  	return new_client;
> > > @@ -3520,8 +3520,8 @@ static int adv76xx_probe(struct i2c_client *client,
> > >  			continue;
> > >  
> > >  		state->i2c_clients[i] = adv76xx_dummy_client(sd, i);
> > > -		if (!state->i2c_clients[i]) {
> > > -			err = -EINVAL;
> > > +		if (IS_ERR(state->i2c_clients[i])) {
> > > +			err = PTR_ERR(state->i2c_clients[i]);
> > >  			v4l2_err(sd, "failed to create i2c client %u\n", i);
> > >  			goto err_i2c;

This will call adv76xx_unregister_clients(), which will try to
i2c_unregister_device() all non-NULL i2c_clients entries. You need to
either set the entry to NULL here, or update
adv76xx_unregister_clients() to skip IS_ERR() entries. My preference
would be to store the return value of adv76xx_dummy_client() in a local
variable here, and set state->i2c_clients[i] after the error check.

> > >  		}
> > > diff --git a/include/linux/i2c.h b/include/linux/i2c.h
> > > index fa5552c2307b..ebbe024dd9e0 100644
> > > --- a/include/linux/i2c.h
> > > +++ b/include/linux/i2c.h
> > > @@ -473,7 +473,7 @@ extern struct i2c_client *
> > >  devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
> > >  
> > >  extern struct i2c_client *
> > > -i2c_new_secondary_device(struct i2c_client *client,
> > > +i2c_new_ancillary_device(struct i2c_client *client,
> > >  				const char *name,
> > >  				u16 default_addr);
> > >  

-- 
Regards,

Laurent Pinchart