Hello.

On 07/13/2013 02:25 AM, Russell King - ARM Linux wrote:

DMA bounce limit is the maximum direct DMA'able memory beyond which
bounce buffers has to be used to perform dma operations. SCSI driver
relies on dma_mask but its calculation is based on max_*pfn which
don't have uniform meaning across architectures. So make use of
dma_max_pfn() which is expected to return the DMAable maximum pfn
value across architectures.

Cc: Russell King <li...@arm.linux.org.uk>
Cc: linux-s...@vger.kernel.org

Signed-off-by: Santosh Shilimkar <santosh.shilim...@ti.com>
---
   drivers/scsi/scsi_lib.c |    2 +-
   1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 86d5220..e8275fa 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1668,7 +1668,7 @@ u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost)

        host_dev = scsi_get_device(shost);
        if (host_dev && host_dev->dma_mask)
-               bounce_limit = *host_dev->dma_mask;
+               bounce_limit = dma_max_pfn(host_dev) << PAGE_SHIFT;

    You definitely forgot -1 here.

Please explain your point.

Previously, 'bounce_limit' would look like 0xffffffff (unless I'm mistaken), now it would look like 0xfffff000 which is hardly what we're looking for, no?

WBR, Sergei

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to