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author | Sughosh Ganu <urwithsughosh@gmail.com> | 2012-02-02 00:44:38 (GMT) |
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committer | Albert ARIBAUD <albert.u.boot@aribaud.net> | 2012-02-12 09:11:33 (GMT) |
commit | da104e04ecc30b90fdc121737f220f0d9c252196 (patch) | |
tree | e86b6dccc5a566b6ac4abe7e3019fd3fb1bd2c48 /arch/arm | |
parent | 27b66622b51f350ce6c143f82d104860ee887f5c (diff) | |
download | u-boot-da104e04ecc30b90fdc121737f220f0d9c252196.tar.xz |
arm, arm926ejs: Flush the data cache before disabling it
The current implementation invalidates the data cache before turning it
off and causes problems on the hawkboard. See the discussion in
http://lists.denx.de/pipermail/u-boot/2012-January/115212.html
According to the ARM926EJ-S Technical Reference Manual, the cache should
be flushed instead.
Also fix the comments to match code.
Signed-off-by: Sughosh Ganu <urwithsughosh@gmail.com>
Rebased and corrected commit message.
Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Tom Rini <trini@ti.com>
Acked-by: Heiko Schocher <hs@denx.de>
Tested-by: Heiko Schocher <hs@denx.de>
Diffstat (limited to 'arch/arm')
-rw-r--r-- | arch/arm/cpu/arm926ejs/start.S | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/arch/arm/cpu/arm926ejs/start.S b/arch/arm/cpu/arm926ejs/start.S index bb4d00b..b39ed8a 100644 --- a/arch/arm/cpu/arm926ejs/start.S +++ b/arch/arm/cpu/arm926ejs/start.S @@ -358,14 +358,18 @@ _dynsym_start_ofs: #ifndef CONFIG_SKIP_LOWLEVEL_INIT cpu_init_crit: /* - * flush v4 I/D caches + * flush D cache before disabling it */ mov r0, #0 - mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */ - mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */ +flush_dcache: + mrc p15, 0, r15, c7, c10, 3 + bne flush_dcache + + mcr p15, 0, r0, c8, c7, 0 /* invalidate TLB */ + mcr p15, 0, r0, c7, c5, 0 /* invalidate I Cache */ /* - * disable MMU stuff and caches + * disable MMU and D cache, and enable I cache */ mrc p15, 0, r0, c1, c0, 0 bic r0, r0, #0x00002300 /* clear bits 13, 9:8 (--V- --RS) */ |