| Message ID | 20230222092636.1984847-1-xiaoning.wang@nxp.com (mailing list archive) |
|---|---|
| State | Deferred |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next,V4,1/2] net: phylink: add a function to resume PHY alone to fix resume issue with WoL enabled | expand |
net-next is closed due to the merge window. Please resubmit after 6.3-rc1. Thanks. On Wed, Feb 22, 2023 at 05:26:35PM +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> > V4: > Many thanks to Jakub and Russel for their suggestions, here are the changes for V4. > - Unify MAC and PHY in comments and subject to uppercase. > - Add subject of the sentence. > - Move && to the end of the line > - Add notice in the comment of function phylink_phy_resume() > --- > drivers/net/phy/phylink.c | 35 +++++++++++++++++++++++++++++++++-- > include/linux/phylink.h | 1 + > 2 files changed, 34 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c > index ea8fcce5b2d9..0be57e9463d9 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; > @@ -1942,8 +1945,12 @@ 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); > } > @@ -2023,6 +2030,30 @@ 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, it can call this function to resume the PHY separately. > + * Then proceed to MAC resume operations. > + * > + * Note: This function MUST ONLY be called before calling phylink_start() > + * in the MAC resume function. > + */ > +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; > + } > + > +} > +EXPORT_SYMBOL_GPL(phylink_phy_resume); > + > /** > * phylink_resume() - handle a network device resume event > * @pl: a pointer to a &struct phylink returned from phylink_create() > diff --git a/include/linux/phylink.h b/include/linux/phylink.h > index c492c26202b5..6edfab5f754c 100644 > --- a/include/linux/phylink.h > +++ b/include/linux/phylink.h > @@ -589,6 +589,7 @@ void phylink_stop(struct phylink *); > > void phylink_suspend(struct phylink *pl, bool mac_wol); > void phylink_resume(struct phylink *pl); > +void phylink_phy_resume(struct phylink *pl); > > void phylink_ethtool_get_wol(struct phylink *, struct ethtool_wolinfo *); > int phylink_ethtool_set_wol(struct phylink *, struct ethtool_wolinfo *); > -- > 2.34.1 > >
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c index ea8fcce5b2d9..0be57e9463d9 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; @@ -1942,8 +1945,12 @@ 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); } @@ -2023,6 +2030,30 @@ 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, it can call this function to resume the PHY separately. + * Then proceed to MAC resume operations. + * + * Note: This function MUST ONLY be called before calling phylink_start() + * in the MAC resume function. + */ +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; + } + +} +EXPORT_SYMBOL_GPL(phylink_phy_resume); + /** * phylink_resume() - handle a network device resume event * @pl: a pointer to a &struct phylink returned from phylink_create() diff --git a/include/linux/phylink.h b/include/linux/phylink.h index c492c26202b5..6edfab5f754c 100644 --- a/include/linux/phylink.h +++ b/include/linux/phylink.h @@ -589,6 +589,7 @@ void phylink_stop(struct phylink *); void phylink_suspend(struct phylink *pl, bool mac_wol); void phylink_resume(struct phylink *pl); +void phylink_phy_resume(struct phylink *pl); void phylink_ethtool_get_wol(struct phylink *, struct ethtool_wolinfo *); int phylink_ethtool_set_wol(struct phylink *, struct ethtool_wolinfo *);
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> V4: Many thanks to Jakub and Russel for their suggestions, here are the changes for V4. - Unify MAC and PHY in comments and subject to uppercase. - Add subject of the sentence. - Move && to the end of the line - Add notice in the comment of function phylink_phy_resume() --- drivers/net/phy/phylink.c | 35 +++++++++++++++++++++++++++++++++-- include/linux/phylink.h | 1 + 2 files changed, 34 insertions(+), 2 deletions(-)