dm9000: clean up edge-triggered irq compatibility
DM9000 uses level-triggered interrupts. Some systems (PXA270) only
support edge-triggered interrupts on GPIOs. Some changes are necessary
to ensure that interrupts are not triggered while the GPIO interrupt is
masked or we will miss the interrupt forever.
* Make some helper functions called dm9000_mask_interrupts() and
dm9000_unmask_interrupts() for readability.
* dm9000_init_dm9000(): ensure that this function always leaves interrupts
masked regardless of the state when it entered the function. This is
primarily to support the situation in dm9000_open where the logic used
to go:
dm9000_open()
dm9000_init_dm9000()
unmask interrupts
request_irq()
If an interrupt occurred between unmasking the interrupt and
requesting the irq, it would be missed forever as the edge event would
never be seen by the GPIO hardware in the PXA270. This allows us to
change the logic to:
dm9000_open()
dm9000_init_dm9000()
dm9000_mask_interrupts()
request_irq()
dm9000_unmask_interrupts()
* dm9000_timeout(), dm9000_drv_resume(): Add the missing
dm9000_unmask_interrupts() now required by the change above.
* dm9000_shutdown(): Use mask helper function
* dm9000_interrupt(): Use mask/unmask helper functions
Signed-off-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed