diff options
| -rw-r--r-- | drivers/usb/storage/scsiglue.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c index 1b35e011a34..e9d6c196a7a 100644 --- a/drivers/usb/storage/scsiglue.c +++ b/drivers/usb/storage/scsiglue.c @@ -129,6 +129,14 @@ static int slave_configure(struct scsi_device *sdev) max_sectors); } + /* Some USB host controllers can't do DMA; they have to use PIO. + * They indicate this by setting their dma_mask to NULL. For + * such controllers we need to make sure the block layer sets + * up bounce buffers in addressable memory. + */ + if (!us->pusb_dev->bus->controller->dma_mask) + blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_HIGH); + /* We can't put these settings in slave_alloc() because that gets * called before the device type is known. Consequently these * settings can't be overridden via the scsi devinfo mechanism. */ |