On Tue, Aug 21, 2012 at 03:22:18PM +0300, Felipe Balbi wrote:
On Tue, Aug 21, 2012 at 05:50:28PM +0530, Poddar, Sourav wrote:
quoted
If I am understanding correctly, if they both uses the same bit we cannot
use both for a particular user. ?
we can, it's just a bit more complex. If a user request both LOW and
HIGH, then you start with HIGH, once it triggers, before calling the
nested IRQ handler, you need to change it LOW. When low triggers, before
calling the nested IRQ handler, you need to change it to HIGH again. And
so on. I'm just not sure if that's valid on linux IRQ subsystem.
The given example was for keypress - usually a system would use edge
triggered interrupts in combination with reading the GPIO state rather
than level triggered interrupts.