Re: [RFC PATCH net-next v2 03/10] net: phy: add helpers to handle sfp phy connect/disconnect

On Tue, Nov 21, 2023 at 10:08:00AM +0000, Russell King (Oracle) wrote:

On Tue, Nov 21, 2023 at 01:57:24AM +0100, Andrew Lunn wrote:

quoted

quoted

+/**
+ * phy_sfp_connect_phy - Connect the SFP module's PHY to the upstream PHY
+ * @upstream: pointer to the upstream phy device
+ * @phy: pointer to the SFP module's phy device
+ *
+ * This helper allows keeping track of PHY devices on the link. It adds the
+ * SFP module's phy to the phy namespace of the upstream phy
+ */
+int phy_sfp_connect_phy(void *upstream, struct phy_device *phy)
+{
+	struct phy_device *phydev = upstream;

Will this function only ever be called from a PHY driver? If so, we
know upstream is PHY. So we can avoid using void * and make it a
struct phy_device *. 

No. This function is hooked into the .connect_phy method of
sfp_upstream_ops, and the SFP bus layer has no idea what the
"upstream" is. In this case, it's a PHY. In the case of phylink,
it's the phylink struct. So no, "struct phy_device *" here will
cause build errors.

O.K, thanks for checking this. It would of been nice to have some
compile time checking what is passed is what we expect in terms of
type, but C does not allow that in this case.

	 Andrew