When using dcache the setup data for the mailbox must be actually written into memory before calling into firmware. Thus flush and invalidate the memory.
Signed-off-by: Alexander Stein alexanders83@web.de --- Changes in v3: * Use ARCH_DMA_MINALIGN instead of fixed 32 * Adjust comment in header
Changes in v2: * Add hint in header about alignment requirements * Invalidate cache after calling into mailbox * round size up to next cacheline size
arch/arm/mach-bcm283x/include/mach/mbox.h | 3 +++ arch/arm/mach-bcm283x/mbox.c | 9 +++++++++ 2 files changed, 12 insertions(+)
diff --git a/arch/arm/mach-bcm283x/include/mach/mbox.h b/arch/arm/mach-bcm283x/include/mach/mbox.h index 54d369c..ff959c8 100644 --- a/arch/arm/mach-bcm283x/include/mach/mbox.h +++ b/arch/arm/mach-bcm283x/include/mach/mbox.h @@ -522,6 +522,9 @@ int bcm2835_mbox_call_raw(u32 chan, u32 send, u32 *recv); * a termination value are expected to immediately follow the header in * memory, as required by the property protocol. * + * Each struct bcm2835_mbox_hdr passed must be allocated with + * ALLOC_CACHE_ALIGN_BUFFER(x, y, z) to ensure proper cache flush/invalidate. + * * Returns 0 for success, any other value for error. */ int bcm2835_mbox_call_prop(u32 chan, struct bcm2835_mbox_hdr *buffer); diff --git a/arch/arm/mach-bcm283x/mbox.c b/arch/arm/mach-bcm283x/mbox.c index 1af9be7..311bd8f 100644 --- a/arch/arm/mach-bcm283x/mbox.c +++ b/arch/arm/mach-bcm283x/mbox.c @@ -111,9 +111,18 @@ int bcm2835_mbox_call_prop(u32 chan, struct bcm2835_mbox_hdr *buffer) dump_buf(buffer); #endif
+ flush_dcache_range((unsigned long)buffer, + (unsigned long)((void *)buffer + + roundup(buffer->buf_size, ARCH_DMA_MINALIGN))); + ret = bcm2835_mbox_call_raw(chan, phys_to_bus((u32)buffer), &rbuffer); if (ret) return ret; + + invalidate_dcache_range((unsigned long)buffer, + (unsigned long)((void *)buffer + + roundup(buffer->buf_size, ARCH_DMA_MINALIGN))); + if (rbuffer != phys_to_bus((u32)buffer)) { printf("mbox: Response buffer mismatch\n"); return -1;