ccio-dma error

My computer frequently crashes with the error message:

 Kernel panic: ccio-dma.c: ccio_alloc_range() I/O MMU is out of mapping resource

This is with kernel pa17.

This occurs during medium to heavy io.

This has also caused my /var/lib/dbkg directory to be missing.

How can I rebuild it?

This error occurs when the ccio driver can not find adequate space in the resource map to complete the dma mapping. Since you are seeing it frequently, try changing the following line in arch/parisc/kernel/ccio-dma.c to see if that helps:

From:

	static unsigned long ccio_mem_ratio = 32;
To:
	static unsigned long ccio_mem_ratio = 4;

You can also look at the the 2 /proc file entries to get an idea what is going on:

/proc/bus/runway/ccio
/proc/bus/runway/ccio-bitmap

The /proc/bus/runway/ccio should give you general information about the hardware and driver. The /proc/bus/runway/ccio-bitmap should give you an idea of how dense the resource bitmap is.

Hopefully this will help you out.

- Ryan