rtl_hard_enable_irq: how long before?

[Ken Teh <teh@phy.anl.gov>]

How long does it take from a call to rtl_hard_enable_irq() before the system
is ready for the next interrupt?

The reason I ask:  I have an interrupt acquisition system that has external
hardware that vetoes further interrupts until I clear it from the rtl code.
It looks something like this:

        rtl_hard_enable_irq(theirq);
        clear_irq_veto();

At high instantaneous interrupt rates, hundreds of kHz, the acquisition
system dies.  I was able to keep it alive in the face of such rates but
adding an hardware delay of 2-3 microsecs after clear_irq_veto() removes the
hardware veto.

Thanks! Ken