On 2021-03-09 19:18, Vincent MAILHOL wrote:
On Wed. 10 Mar 2021 at 03:11, Vincent MAILHOL
<mailhol.vincent@xxxxxxxxxx> wrote:
On Wed. 10 Mar 2021 at 02:27, Jimmy Assarsson <jimmyassarsson@xxxxxxxxx> wrote:
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?
Indeed, this is a leftover. Should have been removed in v11 when I
made the device FIFO size a power of two.
I was not warned by the compiler, probably because this is an inline function.
...
+/**
+ * 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
Absolutely!
+ 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;
+}
Thanks for the two findings, both will be fixed in v13.
Out of curiosity, did you find the two issues throughout a code
review or did you use any kind of static analysis tool?
Code review.
