process_ctrl_td() is too complex and difficult to read. We can clean it
up a lot and maintain same functionality as before. Note that while
cleaning up, one comment was introduced to explain the special case - it
wasn't clear before from code.
Much of the changes are related to removal of duplicated work done in
both process_ctrl_td() and finish_td(). By removing the duplicated code,
we could remove a few local variables and shuffle things around so the
implementation is more straight forward.
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci-ring.c | 103 ++++++++++++++-----------------------------
1 file changed, 32 insertions(+), 71 deletions(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 7acfecc6639a..607bd2d2ab11 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1930,99 +1930,60 @@ static int process_ctrl_td(struct xhci_hcd *xhci, struct xhci_td *td,
union xhci_trb *ep_trb, struct xhci_transfer_event *event,
struct xhci_virt_ep *ep, int *status)
{
- struct xhci_virt_device *xdev;
- struct xhci_ring *ep_ring;
- struct device *dev;
- unsigned int slot_id;
- int ep_index;
- struct xhci_ep_ctx *ep_ctx;
u32 trb_comp_code;
- u32 remaining, requested;
+ u32 remaining;
+ u32 requested;
u32 trb_type;
trb_type = TRB_FIELD_TO_TYPE(le32_to_cpu(ep_trb->generic.field[3]));
- slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
- xdev = xhci->devs[slot_id];
- ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1;
- ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
- ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
requested = td->urb->transfer_buffer_length;
remaining = EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
- dev = xhci_to_hcd(xhci)->self.controller;
+
+ td->urb->actual_length = requested - remaining;
switch (trb_comp_code) {
case COMP_SUCCESS:
- dev_WARN_ONCE(dev, trb_type != TRB_STATUS,
- "ep%d%s: unexpected success! TRB Type %d\n",
- usb_endpoint_num(&td->urb->ep->desc),
- usb_endpoint_dir_in(&td->urb->ep->desc) ?
- "in" : "out", trb_type);
- *status = 0;
- break;
case COMP_SHORT_PACKET:
*status = 0;
break;
case COMP_STOPPED_SHORT_PACKET:
- if (trb_type == TRB_DATA ||
- trb_type == TRB_NORMAL)
- td->urb->actual_length = remaining;
- else
+ if (trb_type == TRB_SETUP ||
+ trb_type == TRB_STATUS)
xhci_warn(xhci, "WARN: Stopped Short Packet on ctrl setup or status TRB\n");
- goto finish_td;
+ *status = -ESHUTDOWN;
+
+ /*
+ * NOTICE: according to section 6.4.2 Table 91 of xHCI rev 1.1
+ * Specification, if completion code is Stopped - Short Packet,
+ * Transfer Length field (referred to as 'remaining' here)
+ * contain the value of EDTLA (see section 4.11.5.2 for
+ * details), which means that remaining contains actual_length,
+ * not the amount of bytes remaining to be transferred as usual.
+ */
+ td->urb->actual_length = remaining;
+ break;
case COMP_STOPPED:
- switch (trb_type) {
- case TRB_SETUP:
+ if (trb_type == TRB_SETUP)
td->urb->actual_length = 0;
- goto finish_td;
- case TRB_DATA:
- case TRB_NORMAL:
- td->urb->actual_length = requested - remaining;
- goto finish_td;
- default:
- xhci_warn(xhci, "WARN: unexpected TRB Type %d\n", trb_type);
- goto finish_td;
- }
+ *status = -ESHUTDOWN;
+ break;
case COMP_STOPPED_LENGTH_INVALID:
- goto finish_td;
- default:
- if (!xhci_requires_manual_halt_cleanup(xhci,
- ep_ctx, trb_comp_code))
- break;
- xhci_dbg(xhci, "TRB error %u, halted endpoint index = %u\n",
- trb_comp_code, ep_index);
- /* else fall through */
+ td->urb->actual_length = 0;
+ *status = -EINVAL;
+ break;
case COMP_STALL_ERROR:
- /* Did we transfer part of the data (middle) phase? */
- if (trb_type == TRB_DATA ||
- trb_type == TRB_NORMAL)
- td->urb->actual_length = requested - remaining;
- else if (!td->urb_length_set)
- td->urb->actual_length = 0;
- goto finish_td;
- }
+ *status = -EINVAL;
- /* stopped at setup stage, no data transferred */
- if (trb_type == TRB_SETUP)
- goto finish_td;
-
- /*
- * if on data stage then update the actual_length of the URB and flag it
- * as set, so it won't be overwritten in the event for the last TRB.
- */
- if (trb_type == TRB_DATA ||
- trb_type == TRB_NORMAL) {
- td->urb_length_set = true;
- td->urb->actual_length = requested - remaining;
- xhci_dbg(xhci, "Waiting for status stage event\n");
- return 0;
+ if (trb_type != TRB_DATA &&
+ trb_type != TRB_NORMAL)
+ td->urb->actual_length = 0;
+ break;
+ default:
+ /* nothing, further processed by finish_td() */
+ break;
}
- /* at status stage */
- if (!td->urb_length_set)
- td->urb->actual_length = requested;
-
-finish_td:
return finish_td(xhci, td, ep_trb, event, ep, status, false);
}
--
2.10.1
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