linux-kernel - Re: [PATCH 4/4] eeprom: at24: provide a separate routine for creating dummy i2c clients

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Date:   Wed, 11 Apr 2018 13:44:38 +0200
From:   Peter Rosin <peda@...ntia.se>
To:     Bartosz Golaszewski <brgl@...ev.pl>,
        Andy Shevchenko <andy.shevchenko@...il.com>,
        Sven Van Asbroeck <svendev@...x.com>
Cc:     linux-i2c@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 4/4] eeprom: at24: provide a separate routine for creating
 dummy i2c clients

On 2018-04-10 15:12, Bartosz Golaszewski wrote:
> Move the code responsible for creating the dummy i2c clients used by
> chips taking multiple slave addresses to a separate function.
> 
> Signed-off-by: Bartosz Golaszewski <brgl@...ev.pl>
> ---
>  drivers/misc/eeprom/at24.c | 47 ++++++++++++++++++++++++++------------
>  1 file changed, 33 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
> index c57eaea181d8..0cf79ca4f1bf 100644
> --- a/drivers/misc/eeprom/at24.c
> +++ b/drivers/misc/eeprom/at24.c
> @@ -540,6 +540,35 @@ static void at24_remove_dummy_clients(struct at24_data *at24)
>  		i2c_unregister_device(at24->client[i].client);
>  }
>  
> +static int at24_make_dummy_client(struct at24_data *at24, unsigned int index,
> +				  struct regmap_config *regmap_config)
> +{
> +	struct i2c_client *base_client, *dummy_client;
> +	unsigned short int addr;
> +	struct regmap *regmap;
> +	struct device *dev;
> +
> +	base_client = at24->client[0].client;
> +	dev = &base_client->dev;
> +	addr = base_client->addr + index;
> +
> +	dummy_client = i2c_new_dummy(base_client->adapter,
> +				     base_client->addr + index);
> +	if (!dummy_client) {
> +		dev_err(dev, "address 0x%02x unavailable\n", addr);
> +		return -EADDRINUSE;
> +	}
> +
> +	regmap = devm_regmap_init_i2c(dummy_client, regmap_config);
> +	if (IS_ERR(regmap))

AFAICT, if regmap init fails and you return early, dummy_client is leaked.

> +		return PTR_ERR(regmap);
> +
> +	at24->client[index].client = dummy_client;
> +	at24->client[index].regmap = regmap;
> +
> +	return 0;
> +}
> +
>  static unsigned int at24_get_offset_adj(u8 flags, unsigned int byte_len)
>  {
>  	if (flags & AT24_FLAG_MAC) {
> @@ -645,20 +674,10 @@ static int at24_probe(struct i2c_client *client)
>  
>  	/* use dummy devices for multiple-address chips */
>  	for (i = 1; i < num_addresses; i++) {
> -		at24->client[i].client = i2c_new_dummy(client->adapter,
> -						       client->addr + i);
> -		if (!at24->client[i].client) {
> -			dev_err(dev, "address 0x%02x unavailable\n",
> -				client->addr + i);
> -			err = -EADDRINUSE;
> -			goto err_clients;
> -		}
> -		at24->client[i].regmap = devm_regmap_init_i2c(
> -						at24->client[i].client,
> -						&regmap_config);
> -		if (IS_ERR(at24->client[i].regmap)) {
> -			err = PTR_ERR(at24->client[i].regmap);
> -			goto err_clients;
> +		err = at24_make_dummy_client(at24, i, &regmap_config);
> +		if (err) {
> +			at24_remove_dummy_clients(at24);
> +			return err;
>  		}
>  	}
>  
>