tree 3911c0883429411e27f22db1e34436d75fbb937b
parent 46bcf14f44d8f31ecfdc8b6708ec15a3b33316d9
author Ben Hutchings <bhutchings@solarflare.com> 1291749885 +0000
committer Ben Hutchings <bhutchings@solarflare.com> 1291750219 +0000

sfc: Fix crash in legacy onterrupt handler during ring reallocation

If we are using a legacy interrupt, our IRQ may be shared and our
interrupt handler may be called even though interrupts are disabled on
the NIC. When we change ring sizes, we reallocate the event queue and
the interrupt handler may use an invalid pointer when called for
another device's interrupt.

Maintain a legacy_irq_enabled flag and test that at the top of the
interrupt handler.  Note that this problem results from the need to
work around broken INT_ISR0 reads, and does not affect the legacy
interrupt handler for Falcon A1.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>