I have an hardware with two ethernet interfaces, and with the two PHYs inside
the same component INTEL LXT973 which has only one interrupt.
I also have another hardware with two ethernet interfaces and two independant
PHYs. But the two PHYs are wired to the same interrupt.
This is working perfectly up to Linux 3.12.
Hm, I'm surprised it works. Are you sure you're getting interrupts from
both PHYs? Because if both Ethernet controllers are active simultaneously,
only the first registered PHY IRQ handler should get all the interrupts.
Yes it works. Why should only the first one get the interrupts ?
handle_irq_event_percpu() (from kernel/irq/handle.c, extract below) calls all
handlers regardless of whether they answer IRQ_NONE or IRQ_HANDLED. The break
applies to the switch(), not to the while(). So all handlers are called.
Reading the commit log, I can't really understand the reason for the change.
Is it really worth it, and therefore how shall my case be handled ?
PHY IRQs are not necessary for the phylib state machine.
However, polling is less efficient than IRQs. It wastes CPU and link loss
detection is slower.
BR
Christophe