On 10/30/2012 01:09 AM, Jayachandran C. wrote:
[...]

We had seen the same issue here, and worked around it the same way
(i.e use dynamic allocation for the backing dev structures).

I ran across a similar issue in using built-in DTB (basically, kernel
data address does not work for virt_to_phys/phys_to_virt in 64-bit
when the load address is in CKSEG0).  There I did something like this:

ptr = phys_to_virt(__pa(kernel_data_ptr));

This works since __pa knows about CKSEG0 addresses in 64bit.

Really the proper fix is to make virt_to_phys() work.  This isn't the 
only case where we have seen failures due to this issue:


http://www.linux-mips.org/archives/linux-mips/2011-09/msg00029.html

I fixed it like this...

In io.h:

static inline unsigned long virt_to_phys(volatile const void *address)
{
	return __pa(address);
}

Really this needs to be pushed upstream by somebody.

JC.