Re: [PATCH v2 03/23] ata: sata_dwc_460ex: set dma_boundary to 0x1fff

From: Tejun Heo
Date: Sun May 08 2016 - 15:41:41 EST


On Tue, Apr 26, 2016 at 12:03:04PM +0300, Andy Shevchenko wrote:
> diff --git a/drivers/ata/sata_dwc_460ex.c b/drivers/ata/sata_dwc_460ex.c
> index 7f95389..aee8873 100644
> --- a/drivers/ata/sata_dwc_460ex.c
> +++ b/drivers/ata/sata_dwc_460ex.c
> @@ -1151,7 +1151,13 @@ static struct scsi_host_template sata_dwc_sht = {
> */
> .sg_tablesize = LIBATA_MAX_PRD,
> /* .can_queue = ATA_MAX_QUEUE, */
> - .dma_boundary = ATA_DMA_BOUNDARY,
> + /*
> + * Make sure a LLI block is not created that will span 8K max FIS
> + * boundary. If the block spans such a FIS boundary, there is a chance
> + * that a DMA burst will cross that boundary -- this results in an
> + * error in the host controller.
> + */
> + .dma_boundary = 0x1fff /* ATA_DMA_BOUNDARY */,

The host controller can't cross 8k boundary? Is this for real?

--
tejun