Re: [PATCH net-next v3 2/4] net: ethernet: altera-tse: Convert to mdio-regmap and use PCS Lynx
From: "Russell King (Oracle)" <linux@armlinux.org.uk>
Date: 2023-05-26 09:06:01
Also in:
linux-arm-kernel, lkml
Subsystem:
ethernet phy library, networking drivers, synopsys designware ethernet xpcs driver, the rest · Maintainers:
Andrew Lunn, Heiner Kallweit, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
On Fri, May 26, 2023 at 10:39:08AM +0200, Simon Horman wrote:
On Fri, May 26, 2023 at 09:42:50AM +0200, Maxime Chevallier wrote:quoted
The newly introduced regmap-based MDIO driver allows for an easy mapping of an mdiodevice onto the memory-mapped TSE PCS, which is actually a Lynx PCS. Convert Altera TSE to use this PCS instead of the pcs-altera-tse, which is nothing more than a memory-mapped Lynx PCS. Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>Hi Maxime, I have some concerns about the error paths in this patch.
We've had similar problems with mdio_device_create() vs the XPCS driver. I think it's time that we made this easier for users.
diff --git a/drivers/net/pcs/pcs-xpcs.c b/drivers/net/pcs/pcs-xpcs.c
index b87c69c4cdd7..802222581feb 100644
--- a/drivers/net/pcs/pcs-xpcs.c
+++ b/drivers/net/pcs/pcs-xpcs.c@@ -1240,6 +1240,7 @@ struct dw_xpcs *xpcs_create(struct mdio_device *mdiodev, if (!xpcs) return ERR_PTR(-ENOMEM); + mdio_device_get(mdiodev); xpcs->mdiodev = mdiodev; xpcs_id = xpcs_get_id(xpcs);
@@ -1272,6 +1273,7 @@ struct dw_xpcs *xpcs_create(struct mdio_device *mdiodev, ret = -ENODEV; out: + mdio_device_put(mdiodev); kfree(xpcs); return ERR_PTR(ret);
@@ -1280,8 +1282,33 @@ EXPORT_SYMBOL_GPL(xpcs_create); void xpcs_destroy(struct dw_xpcs *xpcs) { + mdio_device_put(mdiodev); kfree(xpcs); } EXPORT_SYMBOL_GPL(xpcs_destroy); +struct dw_xpcs *xpcs_create_mdiodev(struct mii_bus *bus, int addr, + phy_interface_t interface) +{ + struct mdio_device *mdiodev; + struct dw_xpcs *xpcs; + + mdiodev = mdio_device_create(bus, addr); + if (IS_ERR(mdiodev)) + return ERR_CAST(mdiodev); + + xpcs = xpcs_create(mdiodev, interface); + + /* xpcs_create() has taken a refcount on the mdiodev if it was + * successful. If xpcs_create() fails, this will free the mdio + * device here. In any case, we don't need to hold our reference + * anymore, and putting it here will allow mdio_device_put() in + * xpcs_destroy() to automatically free the mdio device. + */ + mdio_device_put(mdiodev); + + return xpcs; +} +EXPORT_SYMBOL_GPL(xpcs_create_mdiodev); + MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mdio.h b/include/linux/mdio.h
index 1d7d550bbf1a..537b62330c90 100644
--- a/include/linux/mdio.h
+++ b/include/linux/mdio.h@@ -108,6 +108,16 @@ int mdio_driver_register(struct mdio_driver *drv); void mdio_driver_unregister(struct mdio_driver *drv); int mdio_device_bus_match(struct device *dev, struct device_driver *drv); +static inline void mdio_device_get(struct mdio_device *mdiodev) +{ + get_device(&mdiodev->dev); +} + +static inline void mdio_device_put(struct mdio_device *mdiodev) +{ + mdio_device_free(mdiodev); +} + static inline bool mdio_phy_id_is_c45(int phy_id) { return (phy_id & MDIO_PHY_ID_C45) && !(phy_id & ~MDIO_PHY_ID_C45_MASK);
The same for pcs-lynx. That way we remove the need for driver authors to get the creation and destruction of the mdio device correct without messing up the existing users - they only have to worry about creating the PCS via the xxx_create_mdiodev() function and destroying it via xxx_destroy(). -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!