Messages in this thread |  | | From | Florian Fainelli <> | Date | Wed, 20 Nov 2013 14:36:14 -0800 | Subject | Re: [PATCH RFC v1 4/7] net: phy: suspend unused PHYs on mdio_bus in late_initcall |
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2013/11/20 Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>: > On 11/20/2013 09:58 PM, Florian Fainelli wrote: >> >> 2013/11/20 Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>: >>> >>> Since phy_attach ensures PHYs are resumed, we can now suspend all >>> PHYs that have no attached netdev after initcalls. >> >> >> I do like the idea, but I think you might want to make sure that the >> MDIO bus suspend policy was set to "auto" (which is the default afair) >> not to expose unexpected behavior. > > > Ok, TBH I haven't looked through all of phy internals. If we are fine > with the overall approach, I could use some guidance in the individual > patches and policies. > > >>> >>> Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> >>> --- >>> Cc: David S. Miller <davem@davemloft.net> >>> Cc: netdev@vger.kernel.org >>> Cc: linux-arm-kernel@lists.infradead.org >>> Cc: linux-kernel@vger.kernel.org >>> --- >>> drivers/net/phy/mdio_bus.c | 27 +++++++++++++++++++++++++++ >>> 1 files changed, 27 insertions(+), 0 deletions(-) >>> >>> diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c >>> index 5617876..10eba58 100644 >>> --- a/drivers/net/phy/mdio_bus.c >>> +++ b/drivers/net/phy/mdio_bus.c >>> @@ -320,6 +320,33 @@ static int mdio_bus_match(struct device *dev, struct >>> device_driver *drv) >>> (phydev->phy_id & phydrv->phy_id_mask)); >>> } >>> >>> +static int mdio_bus_suspend_unused(struct device *busdev, void *data) >>> +{ >>> + struct mii_bus *bus = to_mii_bus(busdev); >>> + struct phy_device *phydev; >>> + struct phy_driver *phydrv; >>> + int i; >>> + >>> + for (i = 0; i < PHY_MAX_ADDR; i++) { >>> + if (!bus->phy_map[i]) >>> + continue; >>> + >>> + phydev = to_phy_device(&bus->phy_map[i]->dev); >>> + phydrv = to_phy_driver(phydev->dev.driver); >>> + if (!phydev->attached_dev && phydrv && phydrv->suspend) >>> + phy_suspend(phydev); >>> + } >>> + >>> + return 0; >> >> >> You might want to reuse mdio_bus_phy_may_suspend() here to have a >> central place checking for phydev->attached_dev and phydrv->suspend >> just in case we need to add more callbacks in the future or implicit >> PHY state machine hooks. That might also take care of my concern >> expressed above. > > > Unfortunately, mdio_bus_phy_may_suspend() doesn't help here. It will > correctly tell that unconnected PHYs may_suspend but also that PHYs > connected to PM aware drivers may_suspend.
I agree for the first part which is why I was suggesting it, we are sure we will return early because of the if (!netdev) branch.
> > I tried it and it will also suspend the PHY taken by mv643xx_eth. > > But actually, as phy_suspend/resume check for phydrv->suspend > themselves, we can just call it on !phydev->attached_dev and remove > the additional checks.
Sure, sounds good. -- Florian
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