#include <linux/sched.h>
#include <linux/gfp.h>
#include <linux/errno.h>
+#include <linux/export.h>
#include <linux/usb/quirks.h>
/* COMMAND STAGE */
/* let's send the command via the control pipe */
+ /*
+ * Command is sometime (f.e. after scsi_eh_prep_cmnd) on the stack.
+ * Stack may be vmallocated. So no DMA for us. Make a copy.
+ */
+ memcpy(us->iobuf, srb->cmnd, srb->cmd_len);
result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
US_CBI_ADSC,
USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
- us->ifnum, srb->cmnd, srb->cmd_len);
+ us->ifnum, us->iobuf, srb->cmd_len);
/* check the return code for the command */
US_DEBUGP("Call to usb_stor_ctrl_transfer() returned %d\n", result);
*/
if (result == USB_STOR_XFER_LONG)
fake_sense = 1;
+
+ /*
+ * Sometimes a device will mistakenly skip the data phase
+ * and go directly to the status phase without sending a
+ * zero-length packet. If we get a 13-byte response here,
+ * check whether it really is a CSW.
+ */
+ if (result == USB_STOR_XFER_SHORT &&
+ srb->sc_data_direction == DMA_FROM_DEVICE &&
+ transfer_length - scsi_get_resid(srb) ==
+ US_BULK_CS_WRAP_LEN) {
+ struct scatterlist *sg = NULL;
+ unsigned int offset = 0;
+
+ if (usb_stor_access_xfer_buf((unsigned char *) bcs,
+ US_BULK_CS_WRAP_LEN, srb, &sg,
+ &offset, FROM_XFER_BUF) ==
+ US_BULK_CS_WRAP_LEN &&
+ bcs->Signature ==
+ cpu_to_le32(US_BULK_CS_SIGN)) {
+ US_DEBUGP("Device skipped data phase\n");
+ scsi_set_resid(srb, transfer_length);
+ goto skipped_data_phase;
+ }
+ }
}
/* See flow chart on pg 15 of the Bulk Only Transport spec for
if (result != USB_STOR_XFER_GOOD)
return USB_STOR_TRANSPORT_ERROR;
+ skipped_data_phase:
/* check bulk status */
residue = le32_to_cpu(bcs->Residue);
US_DEBUGP("Bulk Status S 0x%x T 0x%x R %u Stat 0x%x\n",