Accessing copy_to_user() from interrupt handler?

Klaus-Georg Adams (
21 Nov 1996 13:54:02 +0100

Hi all,

I am writing a device driver for an astronomical CCD camera. It works
very reliably when I poll the CCD for data. I would however like to
convert it to an interrupt driven version. The ISA-Bus card has a FIFO
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
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
have to wakeup the process in order to do the copying from the read()

-- kga
Klaus-Georg Adams Email: Klaus-Georg.Adams@Chemie.Uni-Karlsruhe.De
Institut f. Anorg. Chemie II Tel: 0721 608 3485
Uni Karlsruhe