On 10.04.2012 22:18, Mulyadi Santosa wrote:
Hi....
On Wed, Apr 11, 2012 at 03:22, Christopher Harvey <chris@basementcode.com> wrote:
The IRQ and the setting of the devid value happen fairly close to each other in time. (like less than a second, or closer)
Hmmm, and how about the order? which one do you guess go first? setting value? or the IRQ handler?
I had a sense that your code flow might (in reality) goes like this
allocating struct RAM --> interrupted --> printing struct content --> back to initialize struct
If that's true, then no wonder 0 (zero) is printed.
I suggest to grab a spin lock if you really need atomicity during allocation and setting initial value, which in IRQ handler, you grab the lock before printing. Oh and since memory allocation could go slow, you might need to do allocation with GFP_ATOMIC.
well, actually my does does this: set variable->init hardware->interrupt the interrupt can't happen until 'init hardware'