Re: [PATCH] net: phy: Make sure phy_start() always re-enables the phy interrupts

[David Miller <davem@davemloft.net>]

From: Tim Beale <tim.beale@alliedtelesis.co.nz>
Date: Mon, 18 May 2015 15:38:38 +1200

> This is an alternative way of fixing:
>  commit db9683fb412d ("net: phy: Make sure PHY_RESUMING state change
>                       is always processed")
> 
> When the PHY state transitions from PHY_HALTED to PHY_RESUMING, there are
> two things we need to do:
> 1). Re-enable interrupts (and power up the physical link, if powered down)
> 2). Update the PHY state and net-device based on the link status.
> 
> There's no strict reason why #1 has to be done from within the main
> phy_state_machine() function. There is a risk that other changes to the
> PHY (e.g. setting speed/duplex, which calls phy_start_aneg()) could cause
> a subsequent state transition before phy_state_machine() has processed
> the PHY_RESUMING state change. This would leave the PHY with interrupts
> disabled and/or still in the BMCR_PDOWN/low-power mode.
> 
> Moving enabling the interrupts and phy_resume() into phy_start() will
> guarantee this work always gets done. As the PHY is already in the HALTED
> state and interrupts are disabled, it shouldn't conflict with any work
> being done in phy_state_machine(). The downside of this change is that if
> the PHY_RESUMING state is ever entered from anywhere else, it'll also have
> to repeat this work.
> 
> Signed-off-by: Tim Beale <tim.beale@alliedtelesis.co.nz>

Applied.