On some hardware no TX done interrupts are generated, thus special
100Hz timer interrupt is required to handle this situation properly.
Other device do not require that timer interrupt feature.
Forcedeth has a DEV_NEED_TIMERIRQ flag to mark the broken devices.
Unfortunately, nobody know the actual list of broken devices, so all
device has this flag on. Other problem, this flag is not user visible,
so the kernel recompilation is required to disable timer interrupts and
test a device.
This patch add a "disable_timerirq" option to disable interrupt
timer mentioned above. This may be extremely useful for laptop users.