Hello.
On 21-10-2011 10:44, Bas van den Berg wrote:
the cache also needs to be invalidated, not just flushed, Since re-enabling it, can cause inconsistent data without invalidation. See example below.
in c-file: static int num = 1;
void test() { num = 1; dcache_enable(); printf("Cache on, num=%d\n", num); num = 2; dcache_disable(); printf("Cache off, num=%d\n", num); num = 1; dcache_enable(); printf("Cache on, num=%d\n", num); // -> prints 2 instead of 1!! dcache_disable(); printf("Cache off, num=%d\n", num); }
arch/arm/lib/cache.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/arch/arm/lib/cache.c b/arch/arm/lib/cache.c index b545fb7..10eb8c9 100644 --- a/arch/arm/lib/cache.c +++ b/arch/arm/lib/cache.c @@ -37,6 +37,8 @@ void __flush_cache(unsigned long start, unsigned long size) asm("0: mrc p15, 0, r15, c7, c10, 3\n\t" "bne 0b\n" : : : "memory"); /* disable write buffer as well (page 2-22) */ asm("mcr p15, 0, %0, c7, c10, 4" : : "r" (0));
- /* Invalidate dcache as well */
- asm("mcr p15, 0, %0, c7, c6, 0" : : "r" (0));
Please indent with tabs as above.
WBR, Sergei