Re: Accessing copy_to_user() from interrupt handler?

Alan Cox (
Thu, 21 Nov 1996 21:37:59 +0000 (GMT)

> holding 8k Pixels and it sends an interrupt when it is half full. I
> have tried to wake up the process in the interrupt handler, but this
> wasn't reliable under high load (sometimes the wakeup took to long and
> the FIFO overflowed). Now I would like to try reading half a FIFO

You probably want to buffer the data in the kernel, then the mlock isnt
a problem (its up to the user).

> worth of data from the card and copy it to the mlock()'d user buffer
> directly in the interrupt handler. Is this possible at all, or do I

Its 'entertaining'. The ATM folks have played with this a bit. Another
approach is to make the device mmap()able and map the kernel CCD buffer
into user space.