Re: [RFC PATCH net-next 5/9] net: pcs: lynx: Use pcs_get_by_provider to get PCS
From: Vladimir Oltean <olteanv@gmail.com>
Date: 2022-07-19 17:26:38
Also in:
lkml
Subsystem:
networking drivers, networking [dsa], ocelot ethernet switch driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Vladimir Oltean, Linus Torvalds
On Mon, Jul 11, 2022 at 12:05:15PM -0400, Sean Anderson wrote:
quoted hunk ↗ jump to hunk
There is a common flow in several drivers where a lynx PCS is created without a corresponding firmware node. Consolidate these into one helper function. Because we control when the mdiodev is registered, we can add a custom match function which will automatically bind our driver (instead of using device_driver_attach). Signed-off-by: Sean Anderson <redacted> --- drivers/net/dsa/ocelot/felix_vsc9959.c | 25 ++++--------------- drivers/net/dsa/ocelot/seville_vsc9953.c | 25 ++++--------------- .../net/ethernet/freescale/enetc/enetc_pf.c | 21 +++------------- drivers/net/pcs/pcs-lynx.c | 24 ++++++++++++++++++ include/linux/pcs-lynx.h | 1 + 5 files changed, 39 insertions(+), 57 deletions(-)diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c index 57634e2296c0..0a756c25d5e8 100644 --- a/drivers/net/dsa/ocelot/felix_vsc9959.c +++ b/drivers/net/dsa/ocelot/felix_vsc9959.c@@ -11,6 +11,7 @@ #include <net/tc_act/tc_gate.h> #include <soc/mscc/ocelot.h> #include <linux/dsa/ocelot.h> +#include <linux/pcs.h> #include <linux/pcs-lynx.h> #include <net/pkt_sched.h> #include <linux/iopoll.h>@@ -1089,16 +1090,9 @@ static int vsc9959_mdio_bus_alloc(struct ocelot *ocelot) if (ocelot_port->phy_mode == PHY_INTERFACE_MODE_INTERNAL) continue; - mdio_device = mdio_device_create(felix->imdio, port); - if (IS_ERR(mdio_device)) + phylink_pcs = lynx_pcs_create_on_bus(felix->imdio, port); + if (IS_ERR(phylink_pcs)) continue; - - phylink_pcs = lynx_pcs_create(mdio_device); - if (IS_ERR(phylink_pcs)) { - mdio_device_free(mdio_device); - continue; - } - felix->pcs[port] = phylink_pcs; dev_info(dev, "Found PCS at internal MDIO address %d\n", port);@@ -1112,17 +1106,8 @@ static void vsc9959_mdio_bus_free(struct ocelot *ocelot) struct felix *felix = ocelot_to_felix(ocelot); int port; - for (port = 0; port < ocelot->num_phys_ports; port++) { - struct phylink_pcs *phylink_pcs = felix->pcs[port]; - struct mdio_device *mdio_device; - - if (!phylink_pcs) - continue; - - mdio_device = lynx_get_mdio_device(phylink_pcs); - mdio_device_free(mdio_device); - lynx_pcs_destroy(phylink_pcs); - } + for (port = 0; port < ocelot->num_phys_ports; port++) + pcs_put(felix->pcs[port]); mdiobus_unregister(felix->imdio); mdiobus_free(felix->imdio); }diff --git a/drivers/net/dsa/ocelot/seville_vsc9953.c b/drivers/net/dsa/ocelot/seville_vsc9953.c index 8c52de5d0b02..9006dec85ef0 100644 --- a/drivers/net/dsa/ocelot/seville_vsc9953.c +++ b/drivers/net/dsa/ocelot/seville_vsc9953.c@@ -9,6 +9,7 @@ #include <linux/mdio/mdio-mscc-miim.h> #include <linux/of_mdio.h> #include <linux/of_platform.h> +#include <linux/pcs.h> #include <linux/pcs-lynx.h> #include <linux/dsa/ocelot.h> #include <linux/iopoll.h>@@ -1044,16 +1045,9 @@ static int vsc9953_mdio_bus_alloc(struct ocelot *ocelot) if (ocelot_port->phy_mode == PHY_INTERFACE_MODE_INTERNAL) continue; - mdio_device = mdio_device_create(felix->imdio, addr); - if (IS_ERR(mdio_device)) + phylink_pcs = lynx_pcs_create_on_bus(felix->imdio, addr); + if (IS_ERR(phylink_pcs)) continue; - - phylink_pcs = lynx_pcs_create(mdio_device); - if (IS_ERR(phylink_pcs)) { - mdio_device_free(mdio_device); - continue; - } - felix->pcs[port] = phylink_pcs; dev_info(dev, "Found PCS at internal MDIO address %d\n", addr);@@ -1067,17 +1061,8 @@ static void vsc9953_mdio_bus_free(struct ocelot *ocelot) struct felix *felix = ocelot_to_felix(ocelot); int port; - for (port = 0; port < ocelot->num_phys_ports; port++) { - struct phylink_pcs *phylink_pcs = felix->pcs[port]; - struct mdio_device *mdio_device; - - if (!phylink_pcs) - continue; - - mdio_device = lynx_get_mdio_device(phylink_pcs); - mdio_device_free(mdio_device); - lynx_pcs_destroy(phylink_pcs); - } + for (port = 0; port < ocelot->num_phys_ports; port++) + pcs_put(felix->pcs[port]); /* mdiobus_unregister and mdiobus_free handled by devres */ }diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf.c b/drivers/net/ethernet/freescale/enetc/enetc_pf.c index 8c923a93da88..8da7c8644e44 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc_pf.c +++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.c@@ -8,6 +8,7 @@ #include <linux/of_platform.h> #include <linux/of_mdio.h> #include <linux/of_net.h> +#include <linux/pcs.h> #include <linux/pcs-lynx.h> #include "enetc_ierb.h" #include "enetc_pf.h"@@ -827,7 +828,6 @@ static int enetc_imdio_create(struct enetc_pf *pf) struct device *dev = &pf->si->pdev->dev; struct enetc_mdio_priv *mdio_priv; struct phylink_pcs *phylink_pcs; - struct mdio_device *mdio_device; struct mii_bus *bus; int err;@@ -851,16 +851,8 @@ static int enetc_imdio_create(struct enetc_pf *pf) goto free_mdio_bus; } - mdio_device = mdio_device_create(bus, 0); - if (IS_ERR(mdio_device)) { - err = PTR_ERR(mdio_device); - dev_err(dev, "cannot create mdio device (%d)\n", err); - goto unregister_mdiobus; - } - - phylink_pcs = lynx_pcs_create(mdio_device); + phylink_pcs = lynx_pcs_create_on_bus(bus, 0); if (IS_ERR(phylink_pcs)) { - mdio_device_free(mdio_device); err = PTR_ERR(phylink_pcs); dev_err(dev, "cannot create lynx pcs (%d)\n", err); goto unregister_mdiobus;@@ -880,13 +872,8 @@ static int enetc_imdio_create(struct enetc_pf *pf) static void enetc_imdio_remove(struct enetc_pf *pf) { - struct mdio_device *mdio_device; - - if (pf->pcs) { - mdio_device = lynx_get_mdio_device(pf->pcs); - mdio_device_free(mdio_device); - lynx_pcs_destroy(pf->pcs); - } + if (pf->pcs) + pcs_put(pf->pcs); if (pf->imdio) { mdiobus_unregister(pf->imdio); mdiobus_free(pf->imdio);diff --git a/drivers/net/pcs/pcs-lynx.c b/drivers/net/pcs/pcs-lynx.c index 8272072698e4..adb9fd5ce72e 100644 --- a/drivers/net/pcs/pcs-lynx.c +++ b/drivers/net/pcs/pcs-lynx.c@@ -403,6 +403,30 @@ struct phylink_pcs *lynx_pcs_create(struct mdio_device *mdio) } EXPORT_SYMBOL(lynx_pcs_create); +struct phylink_pcs *lynx_pcs_create_on_bus(struct mii_bus *bus, int addr) +{ + struct mdio_device *mdio; + struct phylink_pcs *pcs; + int err; + + mdio = mdio_device_create(bus, addr); + if (IS_ERR(mdio)) + return ERR_CAST(mdio); + + mdio->bus_match = mdio_device_bus_match; + strncpy(mdio->modalias, "lynx-pcs", sizeof(mdio->modalias)); + err = mdio_device_register(mdio);
Yeah, so the reason why mdio_device_register() fails with -EBUSY for the
PCS devices created by felix_vsc9959.c is this:
int mdiobus_register_device(struct mdio_device *mdiodev)
{
int err;
if (mdiodev->bus->mdio_map[mdiodev->addr])
return -EBUSY;
In other words, we already have an existing mdiodev on the bus at
address mdiodev->addr. Funnily enough, that device is actually us.
It was created at MDIO bus creation time, a dummy phydev that no one
connects to, found by mdiobus_scan(). I knew this was taking place,
but forgot/didn't realize the connection with this patch set, and that
dummy phy_device was completely harmless until now.
I can suppress its creation like this:
From b1d1cd1625a27a62fd02598c7015b8ff0afdd28a Mon Sep 17 00:00:00 2001
From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: Tue, 19 Jul 2022 20:15:52 +0300
Subject: [PATCH] net: dsa: ocelot: suppress PHY device scanning on the
internal MDIO bus
This bus contains Lynx PCS devices, and if the lynx-pcs driver ever
decided to call mdio_device_register(), it would fail due to
mdiobus_scan() having created a dummy phydev for the same address
(the PCS responds to standard clause 22 PHY ID registers and can
therefore by autodetected by phylib which thinks it's a PHY).
On the Seville driver, things are a bit more complicated, since bus
creation is handled by mscc_miim_setup() and that is shared with the
dedicated mscc-miim driver. Suppress PHY scanning only for the Seville
internal MDIO bus rather than for the whole mscc-miim driver, since we
know that on NXP T1040, this bus only contains Lynx PCS devices.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
drivers/net/dsa/ocelot/felix_vsc9959.c | 4 ++++
drivers/net/dsa/ocelot/seville_vsc9953.c | 6 +++++-
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c
index 927225e51f05..1ff71f1df316 100644
--- a/drivers/net/dsa/ocelot/felix_vsc9959.c
+++ b/drivers/net/dsa/ocelot/felix_vsc9959.c@@ -1062,6 +1062,10 @@ static int vsc9959_mdio_bus_alloc(struct ocelot *ocelot) bus->read = enetc_mdio_read; bus->write = enetc_mdio_write; bus->parent = dev; + /* Suppress PHY device creation in mdiobus_scan(), + * we have Lynx PCSs + */ + bus->phy_mask = ~0; mdio_priv = bus->priv; mdio_priv->hw = hw; /* This gets added to imdio_regs, which already maps addresses
diff --git a/drivers/net/dsa/ocelot/seville_vsc9953.c b/drivers/net/dsa/ocelot/seville_vsc9953.c
index 9006dec85ef0..9f400867fce3 100644
--- a/drivers/net/dsa/ocelot/seville_vsc9953.c
+++ b/drivers/net/dsa/ocelot/seville_vsc9953.c@@ -1018,12 +1018,16 @@ static int vsc9953_mdio_bus_alloc(struct ocelot *ocelot) rc = mscc_miim_setup(dev, &bus, "VSC9953 internal MDIO bus", ocelot->targets[GCB], ocelot->map[GCB][GCB_MIIM_MII_STATUS & REG_MASK]); - if (rc) { dev_err(dev, "failed to setup MDIO bus\n"); return rc; } + /* Suppress PHY device creation in mdiobus_scan(), + * we have Lynx PCSs + */ + bus->phy_mask = ~0; + /* Needed in order to initialize the bus mutex lock */ rc = devm_of_mdiobus_register(dev, bus, NULL); if (rc < 0) {
--
2.34.1
and then things start working (including traffic).
> + if (err) {
> + mdio_device_free(mdio);
> + return ERR_PTR(err);
> + }
> +
> + pcs = pcs_get_by_provider(&mdio->dev);
> + mdio_device_free(mdio);
> + return pcs;
> +}
> +EXPORT_SYMBOL(lynx_pcs_create_on_bus);
> +
> void lynx_pcs_destroy(struct phylink_pcs *pcs)
> {
> pcs_put(pcs);
> diff --git a/include/linux/pcs-lynx.h b/include/linux/pcs-lynx.h
> index 5712cc2ce775..1c14342bb8c4 100644
> --- a/include/linux/pcs-lynx.h
> +++ b/include/linux/pcs-lynx.h
> @@ -12,6 +12,7 @@
> struct mdio_device *lynx_get_mdio_device(struct phylink_pcs *pcs);
>
> struct phylink_pcs *lynx_pcs_create(struct mdio_device *mdio);
> +struct phylink_pcs *lynx_pcs_create_on_bus(struct mii_bus *bus, int addr);
>
> void lynx_pcs_destroy(struct phylink_pcs *pcs);
>
> --
> 2.35.1.1320.gc452695387.dirty
>