diff mbox series

[net] net: dsa: mv88e6xxx: allow use of PHYs on CPU and DSA ports

Message ID E1mvFhP-00F8Zb-Ul@rmk-PC.armlinux.org.uk (mailing list archive)
State Accepted
Commit 04ec4e6250e5f58b525b08f3dca45c7d7427620e
Delegated to: Netdev Maintainers
Headers show
Series [net] net: dsa: mv88e6xxx: allow use of PHYs on CPU and DSA ports | expand

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netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 1 maintainers not CCed: linux@armlinux.org.uk
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 78 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Russell King (Oracle) Dec. 9, 2021, 9:26 a.m. UTC 
Martyn Welch reports that his CPU port is unable to link where it has
been necessary to use one of the switch ports with an internal PHY for
the CPU port. The reason behind this is the port control register is
left forcing the link down, preventing traffic flow.

This occurs because during initialisation, phylink expects the link to
be down, and DSA forces the link down by synthesising a call to the
DSA drivers phylink_mac_link_down() method, but we don't touch the
forced-link state when we later reconfigure the port.

Resolve this by also unforcing the link state when we are operating in
PHY mode and the PPU is set to poll the PHY to retrieve link status
information.

Reported-by: Martyn Welch <martyn.welch@collabora.com>
Tested-by: Martyn Welch <martyn.welch@collabora.com>
Fixes: 3be98b2d5fbc ("net: dsa: Down cpu/dsa ports phylink will control")
Cc: <stable@vger.kernel.org> # 5.7: 2b29cb9e3f7f: net: dsa: mv88e6xxx: fix "don't use PHY_DETECT on internal PHY's"
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/dsa/mv88e6xxx/chip.c | 64 +++++++++++++++++---------------
 1 file changed, 34 insertions(+), 30 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org Dec. 9, 2021, 5 p.m. UTC | #1 
Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 09 Dec 2021 09:26:47 +0000 you wrote:
> Martyn Welch reports that his CPU port is unable to link where it has
> been necessary to use one of the switch ports with an internal PHY for
> the CPU port. The reason behind this is the port control register is
> left forcing the link down, preventing traffic flow.
> 
> This occurs because during initialisation, phylink expects the link to
> be down, and DSA forces the link down by synthesising a call to the
> DSA drivers phylink_mac_link_down() method, but we don't touch the
> forced-link state when we later reconfigure the port.
> 
> [...]

Here is the summary with links:
  - [net] net: dsa: mv88e6xxx: allow use of PHYs on CPU and DSA ports
    https://git.kernel.org/netdev/net/c/04ec4e6250e5

You are awesome, thank you!
diff mbox series

Patch

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 9f675464efc3..14f87f6ac479 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -698,44 +698,48 @@  static void mv88e6xxx_mac_config(struct dsa_switch *ds, int port,
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
 	struct mv88e6xxx_port *p;
-	int err;
+	int err = 0;
 
 	p = &chip->ports[port];
 
-	/* FIXME: is this the correct test? If we're in fixed mode on an
-	 * internal port, why should we process this any different from
-	 * PHY mode? On the other hand, the port may be automedia between
-	 * an internal PHY and the serdes...
-	 */
-	if ((mode == MLO_AN_PHY) && mv88e6xxx_phy_is_internal(ds, port))
-		return;
-
 	mv88e6xxx_reg_lock(chip);
-	/* In inband mode, the link may come up at any time while the link
-	 * is not forced down. Force the link down while we reconfigure the
-	 * interface mode.
-	 */
-	if (mode == MLO_AN_INBAND && p->interface != state->interface &&
-	    chip->info->ops->port_set_link)
-		chip->info->ops->port_set_link(chip, port, LINK_FORCED_DOWN);
-
-	err = mv88e6xxx_port_config_interface(chip, port, state->interface);
-	if (err && err != -EOPNOTSUPP)
-		goto err_unlock;
 
-	err = mv88e6xxx_serdes_pcs_config(chip, port, mode, state->interface,
-					  state->advertising);
-	/* FIXME: we should restart negotiation if something changed - which
-	 * is something we get if we convert to using phylinks PCS operations.
-	 */
-	if (err > 0)
-		err = 0;
+	if (mode != MLO_AN_PHY || !mv88e6xxx_phy_is_internal(ds, port)) {
+		/* In inband mode, the link may come up at any time while the
+		 * link is not forced down. Force the link down while we
+		 * reconfigure the interface mode.
+		 */
+		if (mode == MLO_AN_INBAND &&
+		    p->interface != state->interface &&
+		    chip->info->ops->port_set_link)
+			chip->info->ops->port_set_link(chip, port,
+						       LINK_FORCED_DOWN);
+
+		err = mv88e6xxx_port_config_interface(chip, port,
+						      state->interface);
+		if (err && err != -EOPNOTSUPP)
+			goto err_unlock;
+
+		err = mv88e6xxx_serdes_pcs_config(chip, port, mode,
+						  state->interface,
+						  state->advertising);
+		/* FIXME: we should restart negotiation if something changed -
+		 * which is something we get if we convert to using phylinks
+		 * PCS operations.
+		 */
+		if (err > 0)
+			err = 0;
+	}
 
 	/* Undo the forced down state above after completing configuration
-	 * irrespective of its state on entry, which allows the link to come up.
+	 * irrespective of its state on entry, which allows the link to come
+	 * up in the in-band case where there is no separate SERDES. Also
+	 * ensure that the link can come up if the PPU is in use and we are
+	 * in PHY mode (we treat the PPU as an effective in-band mechanism.)
 	 */
-	if (mode == MLO_AN_INBAND && p->interface != state->interface &&
-	    chip->info->ops->port_set_link)
+	if (chip->info->ops->port_set_link &&
+	    ((mode == MLO_AN_INBAND && p->interface != state->interface) ||
+	     (mode == MLO_AN_PHY && mv88e6xxx_port_ppu_updates(chip, port))))
 		chip->info->ops->port_set_link(chip, port, LINK_UNFORCED);
 
 	p->interface = state->interface;