In non-coherent DMA mode, kernel uses cache flushing operations to maintain I/O coherency, so scsi's block queue should be aligned to ARCH_DMA_MINALIGN. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx> --- drivers/scsi/scsi_lib.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index f6097b8..800bf2a 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2096,11 +2096,14 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) q->limits.cluster = 0; /* - * set a reasonable default alignment on word boundaries: the - * host and device may alter it using + * set a reasonable default alignment on word/cacheline boundaries: + * the host and device may alter it using * blk_queue_update_dma_alignment() later. */ - blk_queue_dma_alignment(q, 0x03); + if (plat_device_is_coherent(dev)) + blk_queue_dma_alignment(q, 0x04 - 1); + else + blk_queue_dma_alignment(q, dma_get_cache_alignment() - 1); } EXPORT_SYMBOL_GPL(__scsi_init_queue); -- 2.7.0