I'm currently working on a data acquisition driver for a proprietary hardware
ISA-attached to an embedded x86 system running kernel 2.2.15.
My driver works reasonably well with DMA transfers of up to 8192 bytes,
but fails miserably on larger blocks (kernel oops: dereferencing null pointer).
I don't find any more bugs in my own code, so I wonder whether there's a magical
kernel limit involved (8192 bytes equalling exactly two memory pages)?
I do get a proper DMA buffer allocated, I'm using __get_dma_pages() and yes,
with the correct "order" parameter. My driver oopses as soon as the first DMA
transfer starts.
Totally clueless, hoping for hints,
- Bernd
-- bernd kischnick email kisch@mindless.com tel +49-(0)511-18375- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/