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Subject: Re: [RESEND v12] can: usb: etas_es58X: add support for ETAS ES58X CAN
 USB interfaces
To:     Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Cc:     Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>,
        linux-kernel@vger.kernel.org,
        Marc Kleine-Budde <mkl@pengutronix.de>,
        linux-can@vger.kernel.org
References: <20210309120946.1640-1-mailhol.vincent@wanadoo.fr>
 <20210309120946.1640-2-mailhol.vincent@wanadoo.fr>
From:   Jimmy Assarsson <jimmyassarsson@gmail.com>
Message-ID: <45c0b0cc-bfd6-5180-7ad9-51eebc9de3c9@gmail.com>
Date:   Tue, 9 Mar 2021 18:27:41 +0100
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Hi Vincent,

On 2021-03-09 13:09, Vincent Mailhol wrote:
> This driver supports the ES581.4, ES582.1 and ES584.1 interfaces from
> ETAS GmbH (https://www.etas.com/en/products/es58x.php).
...
> diff --git a/drivers/net/can/usb/etas_es58x/es58x_core.c b/drivers/net/can/usb/etas_es58x/es58x_core.c
> new file mode 100644
> index 000000000000..31f907a7b75f
> --- /dev/null
> +++ b/drivers/net/can/usb/etas_es58x/es58x_core.c
...
> +/**
> + * es58x_add_skb_idx() - Increment an index of the loopback FIFO.
> + * @priv: ES58X private parameters related to the network device.
> + * @idx: address of the index to be incremented.
> + * @a: the increment. Must be positive and less or equal to
> + *	@priv->can.echo_skb_max.
> + *
> + * Do a modulus addition: set *@idx to (*@idx + @a) %
> + * @priv->can.echo_skb_max.
> + *
> + * Rationale: the modulus operator % takes a decent amount of CPU
> + * cycles (c.f. other division functions such as
> + * include/linux/math64.h:iter_div_u64_rem()).
> + */
> +static __always_inline void es58x_add_skb_idx(struct es58x_priv *priv,
> +					      u16 *idx, u16 a)

Never used?

...
> +/**
> + * es58x_get_product_info() - Get the product information and print them.
> + * @es58x_dev: ES58X device.
> + *
> + * Do a synchronous call to get the product information.
> + *
> + * Return: zero on success, errno when any error occurs.
> + */
> +static int es58x_get_product_info(struct es58x_device *es58x_dev)
> +{
> +	struct usb_device *udev = es58x_dev->udev;
> +	const int es58x_prod_info_idx = 6;
> +	/* Empirical tests show a prod_info length of maximum 83,
> +	 * below should be more than enough.
> +	 */
> +	const size_t prod_info_len = 127;
> +	char *prod_info;
> +	int ret;
> +
> +	prod_info = kmalloc(prod_info_len, GFP_KERNEL);
> +	if (!prod_info)
> +		return -ENOMEM;
> +
> +	ret = usb_string(udev, es58x_prod_info_idx, prod_info, prod_info_len);
> +	if (ret < 0) {
> +		dev_err(es58x_dev->dev,
> +			"%s: Could not read the product info: %pe\n",
> +			__func__, ERR_PTR(ret));

Missing free

> +		return ret;
> +	} else if (ret >= prod_info_len - 1) {
> +		dev_warn(es58x_dev->dev,
> +			 "%s: Buffer is too small, result might be truncated\n",
> +			 __func__);
> +	}
> +	dev_info(es58x_dev->dev, "Product info: %s\n", prod_info);
> +	kfree(prod_info);
> +
> +	return 0;
> +}


Regards,
jimmy