ARM926 (MX27) D-cache writethrough bug fix.

ARM926 (MX27) D-cache writethrough bug fix.

Patch for ARM926 (MX27) D-cache writethrough bug fix.
Source: linux-arm-kernel list, posted by Gilles Maigne on 11/17/06.

Text from e-mail posting:

arm926_dma_flush_range write the content of dcache in memory when linux
is configured with CONFIG_CPU_DCACHE_WRITETHROUGH ( cache in
write-through) and does not invalidate the virtual address range.
This is wrong for two reasons :
1/ the cache line does not need to be written because the cache is
write-through
2/ the cache line is not invalidated, so next read at this address may
come from the cache, which is wrong because main memory may contain
valid data resulting of a DMA transaction.
This patch applies to linux 2.6.18

http://www.bitshrine.org/gpp/linux-2.6.19.2-mx-arm926_dcache_writethrough_flush_fix.patch

http://www.bitshrine.org/gpp/linux-2.6.22-mx-ARM926-MX27-D-cache-writethrough-bug-fix.patch