@@ -167,13 +167,13 @@ static int tweak_reset_device_cmd(struct urb *urb)
/*
* clear_halt, set_interface, and set_configuration require special tricks.
*/
-static void tweak_special_requests(struct urb *urb)
+static int tweak_special_requests(struct urb *urb)
{
if (!urb || !urb->setup_packet)
- return;
+ return 0;
if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
- return;
+ return 0;
if (is_clear_halt_cmd(urb))
/* tweak clear_halt */
@@ -189,8 +189,12 @@ static void tweak_special_requests(struct urb *urb)
else if (is_reset_device_cmd(urb))
tweak_reset_device_cmd(urb);
- else
+ else {
usbip_dbg_stub_rx("no need to tweak\n");
+ return 0;
+ }
+
+ return 1;
}
/*
@@ -468,6 +472,7 @@ static void stub_recv_cmd_submit(struct stub_device *sdev,
int support_sg = 1;
int np = 0;
int ret, i;
+ int is_tweaked;
if (pipe == -1)
return;
@@ -580,8 +585,7 @@ static void stub_recv_cmd_submit(struct stub_device *sdev,
priv->urbs[i]->pipe = pipe;
priv->urbs[i]->complete = stub_complete;
- /* no need to submit an intercepted request, but harmless? */
- tweak_special_requests(priv->urbs[i]);
+ is_tweaked = tweak_special_requests(priv->urbs[i]);
masking_bogus_flags(priv->urbs[i]);
}
@@ -594,22 +598,32 @@ static void stub_recv_cmd_submit(struct stub_device *sdev,
/* urb is now ready to submit */
for (i = 0; i < priv->num_urbs; i++) {
- ret = usb_submit_urb(priv->urbs[i], GFP_KERNEL);
+ if (!is_tweaked) {
+ ret = usb_submit_urb(priv->urbs[i], GFP_KERNEL);
- if (ret == 0)
- usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
- pdu->base.seqnum);
- else {
- dev_err(&udev->dev, "submit_urb error, %d\n", ret);
- usbip_dump_header(pdu);
- usbip_dump_urb(priv->urbs[i]);
+ if (ret == 0)
+ usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
+ pdu->base.seqnum);
+ else {
+ dev_err(&udev->dev, "submit_urb error, %d\n", ret);
+ usbip_dump_header(pdu);
+ usbip_dump_urb(priv->urbs[i]);
+ /*
+ * Pessimistic.
+ * This connection will be discarded.
+ */
+ usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
+ break;
+ }
+ } else {
/*
- * Pessimistic.
- * This connection will be discarded.
+ * An identical URB was already submitted in
+ * tweak_special_requests(). Skip submitting this URB to not
+ * duplicate the request.
*/
- usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
- break;
+ priv->urbs[i]->status = 0;
+ stub_complete(priv->urbs[i]);
}
}
Skip submitting URBs, when identical requests were already sent in tweak_special_requests(). Instead call the completion handler directly to return the result of the URB. Even though submitting those requests twice should be harmless, there are USB devices that react poorly to some duplicated requests. One example is the ChipIdea controller implementation in U-Boot: The second SET_CONFIURATION request makes U-Boot disable and re-enable all endpoints. Re-enabling an endpoint in the ChipIdea controller, however, was broken until U-Boot commit b272c8792502 ("usb: ci: Fix gadget reinit"). Signed-off-by: Simon Holesch <simon@holesch.de> --- Changes in v2: - explain change in commit message Thanks for the feedback! drivers/usb/usbip/stub_rx.c | 50 ++++++++++++++++++++++++------------- 1 file changed, 32 insertions(+), 18 deletions(-)