Messages in this thread Patches in this message | | | Date | Tue, 10 Dec 2019 11:38:30 +0000 | From | Russell King - ARM Linux admin <> | Subject | Re: [PATCH 1/3] net: macb: fix for fixed-link mode |
| |
On Tue, Dec 10, 2019 at 09:14:13AM +0000, Milind Parab wrote: > >> This patch fix the issue with fixed link. With fixed-link > >> device opening fails due to macb_phylink_connect not > >> handling fixed-link mode, in which case no MAC-PHY connection > >> is needed and phylink_connect return success (0), however > >> in current driver attempt is made to search and connect to > >> PHY even for fixed-link. > >> > >> Signed-off-by: Milind Parab <mparab@cadence.com> > >> --- > >> drivers/net/ethernet/cadence/macb_main.c | 17 ++++++++--------- > >> 1 file changed, 8 insertions(+), 9 deletions(-) > >> > >> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c > >> index 9c767ee252ac..6b68ef34ab19 100644 > >> --- a/drivers/net/ethernet/cadence/macb_main.c > >> +++ b/drivers/net/ethernet/cadence/macb_main.c > >> @@ -615,17 +615,13 @@ static int macb_phylink_connect(struct macb *bp) > >> { > >> struct net_device *dev = bp->dev; > >> struct phy_device *phydev; > >> + struct device_node *dn = bp->pdev->dev.of_node; > >> int ret; > >> > >> - if (bp->pdev->dev.of_node && > >> - of_parse_phandle(bp->pdev->dev.of_node, "phy-handle", 0)) { > >> - ret = phylink_of_phy_connect(bp->phylink, bp->pdev- > >>dev.of_node, > >> - 0); > >> - if (ret) { > >> - netdev_err(dev, "Could not attach PHY (%d)\n", ret); > >> - return ret; > >> - } > >> - } else { > >> + if (dn) > >> + ret = phylink_of_phy_connect(bp->phylink, dn, 0); > >> + > >> + if (!dn || (ret && !of_parse_phandle(dn, "phy-handle", 0))) { > > > >Hi, > >If of_parse_phandle() returns non-null, the device_node it returns will > >have its reference count increased by one. That reference needs to be > >put. > > > > Okay, as per your suggestion below addition will be okay to store the "phy_node" and then of_node_put(phy_node) on error > > phy_node = of_parse_phandle(dn, "phy-handle", 0); > if (!dn || (ret && !phy_node)) { > phydev = phy_find_first(bp->mii_bus); ... > if (phy_node) > of_node_put(phy_node);
As you're only interested in whether phy-handle exists or not, you could do this instead:
phy_node = of_parse_phandle(dn, "phy-handle", 0); of_node_put(phy_node); if (!dn || (ret && !phy_node)) { ...
Yes, it looks a bit weird, but the only thing you're interested in here is whether of_parse_phandle() returned NULL or non-NULL. You're not interested in dereferencing the pointer.
Some may raise some eye-brows at that, so it may be better to have this as a helper:
static bool macb_phy_handle_exists(struct device_node *dn) { dn = of_parse_phandle(dn, "phy-handle", 0); of_node_put(dn); return dn != NULL; }
and use it as:
if (!dn || (ret && !macb_phy_handle_exists(dn))) {
which is more obvious what is going on.
> > return ret; > > >I assume you're trying to determine whether phylink_of_phy_connect() > >failed because of a missing phy-handle rather than of_phy_attach() > >failing? Maybe those two failures ought to be distinguished by errno > >return value? > > Yes, PHY will be scanned only if phylink_of_phy_connect() returns error due to missing "phy-handle". > Currently, phylink_of_phy_connect() returns same error for missing "phy-handle" and of_phy_attach() failure. > > >of_phy_attach() may fail due to of_phy_find_device() failing to find > >the PHY, or phy_attach_direct() failing. We could switch from using > >of_phy_attach(), to using of_phy_find_device() directly so we can then > >propagate phy_attach_direct()'s error code back, rather than losing it. > >That would then leave the case of of_phy_find_device() failure to be > >considered in terms of errno return value.
Here's a patch I quickly knocked up that does this - may not apply to the kernel you're using as there's a whole bunch of work I have outstanding, but gives the outline idea. Does this help?
8<=== From: Russell King <rmk+kernel@armlinux.org.uk> Subject: [PATCH] net: phylink: avoid of_phy_attach()
of_phy_attach() hides the return value of phy_attach_direct(), forcing us to return a "generic" ENODEV error code that is indistinguishable from the lack-of-phy-property case.
Switch to using of_phy_find_device() to find the PHY device, and then propagating any phy_attach_direct() error back to the caller.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> --- drivers/net/phy/phylink.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c index e9036b72114c..5a5109428d9e 100644 --- a/drivers/net/phy/phylink.c +++ b/drivers/net/phy/phylink.c @@ -887,14 +887,17 @@ int phylink_of_phy_connect(struct phylink *pl, struct device_node *dn, return 0; } - phy_dev = of_phy_attach(pl->netdev, phy_node, flags, - pl->link_interface); + phy_dev = of_phy_find_device(phy_node); /* We're done with the phy_node handle */ of_node_put(phy_node); - if (!phy_dev) return -ENODEV; + ret = phy_attach_direct(pl->netdev, phy_dev, flags, + pl->link_interface); + if (ret) + return ret; + ret = phylink_bringup_phy(pl, phy_dev, pl->link_config.interface); if (ret) phy_detach(phy_dev); -- 2.20.1
-- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up
| |