Do you have a read barrier in the IRQ? See "SMP BARRIER PAIRING" in: http://www.kernel.org/doc/Documentation/memory-barriers.txt -- Wink On Wed, Apr 11, 2012 at 4:59 AM, Christopher Harvey <chris@basementcode.com>wrote:
On 10.04.2012 19:58, Wink Saville wrote:
Sounds to me like there needs to be a flush of the processor cache by using memory barriers.
I used a wmb(); right after I set the value I wanted.
I'm guessing that the IRQ is taken on a different thread and possibly a different processor and the value needs to be flushed. You might try having devid be an atomic_t and then use atomic_set and atomic_read so that the "proper" memory barriers are used.
should I use atomic ops instead of a wmb? The interrupt can't happen until the value is assigned completely in one thread. I'm sure.
_______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies