Stop Endpoint command can come at any point and we
have no control of that. We should make sure to
handle COMP_STOP on SETUP phase as well, otherwise
urb->actual_lenght might be set to negative values
in some occasions such as below:
urb->length = 4;
build_control_transfer_td_for(urb, ep);
stop_endpoint(ep);
COMP_STOP:
[...]
urb->actual_length = urb->length - trb->length;
trb->length is 8 for SETUP stage (8 control request
bytes), so actual_length would be set to -4 in this
case.
While doing that, also make sure to use TRB_TYPE
field of the actual TRB instead of matching pointers
to figure out in which stage of the control transfer
we got our completion event.
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci-ring.c | 30 ++++++++++++++++++------------
1 file changed, 18 insertions(+), 12 deletions(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 76402b44f832..70067b81cc8f 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1939,8 +1939,9 @@ static int process_ctrl_td(struct xhci_hcd *xhci, struct xhci_td *td,
struct xhci_ep_ctx *ep_ctx;
u32 trb_comp_code;
u32 remaining, requested;
- bool on_data_stage;
+ 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;
@@ -1950,14 +1951,11 @@ static int process_ctrl_td(struct xhci_hcd *xhci, struct xhci_td *td,
requested = td->urb->transfer_buffer_length;
remaining = EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
- /* not setup (dequeue), or status stage means we are at data stage */
- on_data_stage = (ep_trb != ep_ring->dequeue && ep_trb != td->last_trb);
-
switch (trb_comp_code) {
case COMP_SUCCESS:
- if (ep_trb != td->last_trb) {
+ if (trb_type != TRB_STATUS) {
xhci_warn(xhci, "WARN: Success on ctrl %s TRB without IOC set?\n",
- on_data_stage ? "data" : "setup");
+ (trb_type == TRB_DATA) ? "data" : "setup");
*status = -ESHUTDOWN;
break;
}
@@ -1967,15 +1965,23 @@ static int process_ctrl_td(struct xhci_hcd *xhci, struct xhci_td *td,
*status = 0;
break;
case COMP_STOP_SHORT:
- if (on_data_stage)
+ if (trb_type == TRB_DATA)
td->urb->actual_length = remaining;
else
xhci_warn(xhci, "WARN: Stopped Short Packet on ctrl setup or status TRB\n");
goto finish_td;
case COMP_STOP:
- if (on_data_stage)
+ switch (trb_type) {
+ case TRB_SETUP:
+ td->urb->actual_length = 0;
+ goto finish_td;
+ case TRB_DATA:
td->urb->actual_length = requested - remaining;
- goto finish_td;
+ goto finish_td;
+ default:
+ xhci_warn(xhci, "WARN: unexpected TRB Type %d\n", trb_type);
+ goto finish_td;
+ }
case COMP_STOP_INVAL:
goto finish_td;
default:
@@ -1987,7 +1993,7 @@ static int process_ctrl_td(struct xhci_hcd *xhci, struct xhci_td *td,
/* else fall through */
case COMP_STALL:
/* Did we transfer part of the data (middle) phase? */
- if (on_data_stage)
+ if (trb_type == TRB_DATA)
td->urb->actual_length = requested - remaining;
else if (!td->urb_length_set)
td->urb->actual_length = 0;
@@ -1995,14 +2001,14 @@ static int process_ctrl_td(struct xhci_hcd *xhci, struct xhci_td *td,
}
/* stopped at setup stage, no data transferred */
- if (ep_trb == ep_ring->dequeue)
+ 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 (on_data_stage) {
+ if (trb_type == TRB_DATA) {
td->urb_length_set = true;
td->urb->actual_length = requested - remaining;
xhci_dbg(xhci, "Waiting for status stage event\n");
--
2.10.1
--
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