Messages in this thread | | | Subject | Re: [PATCH V3 1/2] net: phylink: add a function to resume phy alone to fix resume issue with WoL enabled | From | Paolo Abeni <> | Date | Thu, 23 Feb 2023 11:09:04 +0100 |
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On Thu, 2023-02-02 at 16:15 +0800, Clark Wang wrote: > Issue we met: > On some platforms, mac cannot work after resumed from the suspend with WoL > enabled. > > The cause of the issue: > 1. phylink_resolve() is in a workqueue which will not be executed immediately. > This is the call sequence: > phylink_resolve()->phylink_link_up()->pl->mac_ops->mac_link_up() > For stmmac driver, mac_link_up() will set the correct speed/duplex... > values which are from link_state. > 2. In stmmac_resume(), it will call stmmac_hw_setup() after called the > phylink_resume(), because mac need phy rx_clk to do the reset. > stmmac_core_init() is called in function stmmac_hw_setup(), which will > reset the mac and set the speed/duplex... to default value. > Conclusion: Because phylink_resolve() cannot determine when it is called, it > cannot be guaranteed to be called after stmmac_core_init(). > Once stmmac_core_init() is called after phylink_resolve(), > the mac will be misconfigured and cannot be used. > > In order to avoid this problem, add a function called phylink_phy_resume() > to resume phy separately. This eliminates the need to call phylink_resume() > before stmmac_hw_setup(). > > Add another judgement before called phy_start() in phylink_start(). This way > phy_start() will not be called multiple times when resumes. At the same time, > it may not affect other drivers that do not use phylink_phy_resume(). > > Signed-off-by: Clark Wang <xiaoning.wang@nxp.com> > --- > V2 change: > - add mac_resume_phy_separately flag to struct phylink to mark if the mac > driver uses the phylink_phy_resume() first. > V3 change: > - add brace to avoid ambiguous 'else' > Reported-by: kernel test robot <lkp@intel.com> > --- > drivers/net/phy/phylink.c | 32 ++++++++++++++++++++++++++++++-- > include/linux/phylink.h | 1 + > 2 files changed, 31 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c > index 319790221d7f..c2fe66f0b78f 100644 > --- a/drivers/net/phy/phylink.c > +++ b/drivers/net/phy/phylink.c > @@ -80,6 +80,8 @@ struct phylink { > DECLARE_PHY_INTERFACE_MASK(sfp_interfaces); > __ETHTOOL_DECLARE_LINK_MODE_MASK(sfp_support); > u8 sfp_port; > + > + bool mac_resume_phy_separately; > }; > > #define phylink_printk(level, pl, fmt, ...) \ > @@ -1509,6 +1511,7 @@ struct phylink *phylink_create(struct phylink_config *config, > return ERR_PTR(-EINVAL); > } > > + pl->mac_resume_phy_separately = false; > pl->using_mac_select_pcs = using_mac_select_pcs; > pl->phy_state.interface = iface; > pl->link_interface = iface; > @@ -1943,8 +1946,12 @@ void phylink_start(struct phylink *pl) > } > if (poll) > mod_timer(&pl->link_poll, jiffies + HZ); > - if (pl->phydev) > - phy_start(pl->phydev); > + if (pl->phydev) { > + if (!pl->mac_resume_phy_separately) > + phy_start(pl->phydev); > + else > + pl->mac_resume_phy_separately = false; > + } > if (pl->sfp_bus) > sfp_upstream_start(pl->sfp_bus); > } > @@ -2024,6 +2031,27 @@ void phylink_suspend(struct phylink *pl, bool mac_wol) > } > EXPORT_SYMBOL_GPL(phylink_suspend); > > +/** > + * phylink_phy_resume() - resume phy alone > + * @pl: a pointer to a &struct phylink returned from phylink_create() > + * > + * In the MAC driver using phylink, if the MAC needs the clock of the phy > + * when it resumes, can call this function to resume the phy separately. > + * Then proceed to MAC resume operations. > + */ > +void phylink_phy_resume(struct phylink *pl) > +{ > + ASSERT_RTNL(); > + > + if (!test_bit(PHYLINK_DISABLE_MAC_WOL, &pl->phylink_disable_state) > + && pl->phydev) { > + phy_start(pl->phydev); > + pl->mac_resume_phy_separately = true; > + } > +
Minor nit: the empty line here is not needed.
Cheers,
Paolo
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