diff options
| author | Quinn Jensen <quinn.jensen@freescale.com> | 2007-04-04 17:45:59 -0600 |
|---|---|---|
| committer | Quinn Jensen <quinn.jensen@freescale.com> | 2007-05-24 16:26:26 -0600 |
| commit | 4cb875484e494df06acf346898d8c5c7ebb746eb (patch) | |
| tree | 0adf59f2855d320421a2245e40aea03abda10331 /arch | |
| parent | 78947a2f2dd87f25c82f8c5239e102671f340c82 (diff) | |
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
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/mm/proc-arm926.S | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/mm/proc-arm926.S b/arch/arm/mm/proc-arm926.S index 44a7a652d625..879fb492e6ee 100644 --- a/arch/arm/mm/proc-arm926.S +++ b/arch/arm/mm/proc-arm926.S @@ -291,7 +291,7 @@ ENTRY(arm926_dma_flush_range) #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry #else - mcr p15, 0, r0, c7, c10, 1 @ clean D entry + mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry #endif add r0, r0, #CACHE_DLINESIZE cmp r0, r1 |