Ralf Baechle wrote:

>>+static void r5k_dma_cache_wback_inv_sc(unsigned long addr, unsigned long size)
>>+static void r5k_dma_cache_inv_sc(unsigned long addr, unsigned long size)
>>
>
>You can hook the second level cache support into the bcache hook.  That's
>working because unlike the R4000SC the R5000's second level cache does not
>have the additional constraint of the primary caches always being a subset
>of the second level caches.
>
>Arch/mips/sgi-ip22/ip22-sc.c is an example how this can be done.
>
>
>
This is all very fine in theory but the R5000 cache routines are 
automatically
selected by the R4000 secondary setup routines which pick out the incorrect
flush_range function and wback_inv and inv functions. These do not call
board cache routines at all.

It must be that the secondary cache for the ip22 architecture with an R5000
is not flagged as having a secondary cache in a way that the R4000 
secondary
cache routines can detect.

On the other hand with the application of this (attached) patch the 
cache is
detected correctly and appropriate routines are selected.

/Brian