static int slave_alloc (struct scsi_device *sdev)
{
struct us_data *us = host_to_us(sdev->host);
/*
* Set the INQUIRY transfer length to 36. We don't use any of
* the extra data and many devices choke if asked for more or
* less than 36 bytes.
*/
sdev->inquiry_len = 36;
/* USB has unusual DMA-alignment requirements: Although the
* starting address of each scatter-gather element doesn't matter,
* the length of each element except the last must be divisible
* by the Bulk maxpacket value. There's currently no way to
* express this by block-layer constraints, so we'll cop out
* and simply require addresses to be aligned at 512-byte
* boundaries. This is okay since most block I/O involves
* hardware sectors that are multiples of 512 bytes in length,
* and since host controllers up through USB 2.0 have maxpacket
* values no larger than 512.
*
* But it doesn't suffice for Wireless USB, where Bulk maxpacket
* values can be as large as 2048. To make that work properly
* will require changes to the block layer.
*/
blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
/* Tell the SCSI layer if we know there is more than one LUN */
if (us->protocol == USB_PR_BULK && us->max_lun > 0)
sdev->sdev_bflags |= BLIST_FORCELUN;
return 0;
}
static int slave_alloc (struct scsi_device *sdev)
{
struct us_data *us = host_to_us(sdev->host);
int maxp;
/*
* Set the INQUIRY transfer length to 36. We don't use any of
* the extra data and many devices choke if asked for more or
* less than 36 bytes.
*/
sdev->inquiry_len = 36;
/*
* USB has unusual scatter-gather requirements: the length of each
* scatterlist element except the last must be divisible by the
* Bulk maxpacket value. Fortunately this value is always a
* power of 2. Inform the block layer about this requirement.
*/
maxp = usb_maxpacket(us->pusb_dev, us->recv_bulk_pipe, 0);
blk_queue_virt_boundary(sdev->request_queue, maxp - 1);
/*
* Some host controllers may have alignment requirements.
* We'll play it safe by requiring 512-byte alignment always.
*/
blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
/* Tell the SCSI layer if we know there is more than one LUN */
if (us->protocol == USB_PR_BULK && us->max_lun > 0)
sdev->sdev_bflags |= BLIST_FORCELUN;
return 0;
}
/*
* slave_alloc()
*/
static int slave_alloc(struct scsi_device *sdev)
{
struct us_data *us = host_to_us(sdev->host);
/* pr_info("scsiglue --- slave_alloc\n"); */
sdev->inquiry_len = 36;
blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
if (us->subclass == USB_SC_UFI)
sdev->sdev_target->pdt_1f_for_no_lun = 1;
return 0;
}
static int slave_alloc (struct scsi_device *sdev)
{
struct us_data *us = host_to_us(sdev->host);
/*
* Set the INQUIRY transfer length to 36. We don't use any of
* the extra data and many devices choke if asked for more or
* less than 36 bytes.
*/
sdev->inquiry_len = 36;
/* USB has unusual DMA-alignment requirements: Although the
* starting address of each scatter-gather element doesn't matter,
* the length of each element except the last must be divisible
* by the Bulk maxpacket value. There's currently no way to
* express this by block-layer constraints, so we'll cop out
* and simply require addresses to be aligned at 512-byte
* boundaries. This is okay since most block I/O involves
* hardware sectors that are multiples of 512 bytes in length,
* and since host controllers up through USB 2.0 have maxpacket
* values no larger than 512.
*
* But it doesn't suffice for Wireless USB, where Bulk maxpacket
* values can be as large as 2048. To make that work properly
* will require changes to the block layer.
*/
blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
/*
* The UFI spec treates the Peripheral Qualifier bits in an
* INQUIRY result as reserved and requires devices to set them
* to 0. However the SCSI spec requires these bits to be set
* to 3 to indicate when a LUN is not present.
*
* Let the scanning code know if this target merely sets
* Peripheral Device Type to 0x1f to indicate no LUN.
*/
if (us->subclass == US_SC_UFI)
sdev->sdev_target->pdt_1f_for_no_lun = 1;
return 0;
}
