First of several patches forwarded to me by Sergei Shtylyov. Ralf,
these should be good to go for the tree.
Retain the write-only OD bit from being clobbered by coherency_setup()
Signed-off-by: Sergei Shtylyov <firstname.lastname@example.org>
Acked-by: Jordan Crouse <email@example.com>
arch/mips/mm/c-r4k.c | 14 ++++++++++++++
1 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index 38223b4..044c468 100644
@@ -29,6 +29,10 @@
#include <asm/cacheflush.h> /* for run_uncached() */
* Must die.
@@ -1203,6 +1207,16 @@ static inline void coherency_setup(void)
+ * c0_config.od (bit 19) is write only (and reads as 0) on many early
+ * revs of AMD Au1x00 SOCs. It disables the bus transaction overlapping
+ * and needs to be set to correct the various errata. So if it has been
+ * set by the board setup code we must leave it set...
+ if (cur_cpu_spec->cpu_od)
+ set_c0_config(1 << 19);
* c0_status.cu=0 specifies that updates by the sc instruction use
* the coherency mode specified by the TLB; 1 means cachable