On Mon, Jan 22, 2024 at 10:45:30AM +0200, Danielle Ratson wrote:

+#define MODULE_EEPROM_PAGE	0
+#define MODULE_EEPROM_OFFSET	0
+#define MODULE_EEPROM_LENGTH	1
+#define MODULE_EEPROM_I2C_ADDR	0x50
+
+static int module_flash_fw_work_init(struct ethtool_module_fw_flash *module_fw,
+				     struct net_device *dev,
+				     struct netlink_ext_ack *extack)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct ethtool_module_eeprom page_data = {};
+	struct module_sff8024_id_rpl *rpl;
+	int err;
+
+	/* Fetch the SFF-8024 Identifier Value. For all supported standards, it
+	 * is located at I2C address 0x50, byte 0. See section 4.1 in SFF-8024,
+	 * revision 4.9.
+	 */
+	page_data.page = MODULE_EEPROM_PAGE;
+	page_data.offset = MODULE_EEPROM_OFFSET;
+	page_data.length = MODULE_EEPROM_LENGTH;
+	page_data.i2c_address = MODULE_EEPROM_I2C_ADDR;

Please use better names - these aren't any better than using integers.

Maybe use SFP_PHYS_ID for the offset?

+	page_data.data = kmalloc(page_data.length, GFP_KERNEL);
+	if (!page_data.data)
+		return -ENOMEM;
+
+	err = ops->get_module_eeprom_by_page(dev, &page_data, extack);
+	if (err < 0)
+		goto out;
+
+	rpl = (struct module_sff8024_id_rpl *)page_data.data;

What purpose does this structure of a single byte serve? To me, it just
obfuscates the code.

	u8 phys_id;

	...
	page_data.offset = SFP_PHYS_ID;
	page_data.length = sizeof(phys_id);
	page_data.data = &phys_id;
	...
	switch (phys_id) {

will work just as well, and be more explicit about what's actually going
on here. It doesn't mean that I have to understand what this new
module_sff8024_id_rpl structure is. I can see that we're just getting
one byte which is the module physical ID.

You also then don't need to care about kfree()ing one byte of data
structure.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!