+/* read_ctrl_callback
+ * USB completion handler for control pipe input
+ * called by the USB subsystem in interrupt context
+ * parameter:
+ * urb USB request block
+ * urb->context = inbuf structure for controller state
+ */
+static void read_ctrl_callback(struct urb *urb, struct pt_regs *regs)
+{
+ struct inbuf_t *inbuf = urb->context;
+ struct cardstate *cs = inbuf->cs;
+ struct bas_cardstate *ucs = cs->hw.bas;
+ int have_data = 0;
+ unsigned numbytes;
+ int rc;
+
+ update_basstate(ucs, 0, BS_ATRDPEND);
+
+ if (!ucs->rcvbuf_size) {
+ dev_warn(cs->dev, "%s: no receive in progress\n", __func__);
+ return;
+ }
+
+ del_timer(&ucs->timer_cmd_in);
+
+ switch (urb->status) {
+ case 0: /* normal completion */
+ numbytes = urb->actual_length;
+ if (unlikely(numbytes != ucs->rcvbuf_size)) {
+ dev_warn(cs->dev,
+ "control read: received %d chars, expected %d\n",
+ numbytes, ucs->rcvbuf_size);
+ if (numbytes > ucs->rcvbuf_size)
+ numbytes = ucs->rcvbuf_size;
+ }
+
+ /* copy received bytes to inbuf */
+ have_data = gigaset_fill_inbuf(inbuf, ucs->rcvbuf, numbytes);
+
+ if (unlikely(numbytes < ucs->rcvbuf_size)) {
+ /* incomplete - resubmit for remaining bytes */
+ ucs->rcvbuf_size -= numbytes;
+ ucs->retry_cmd_in = 0;
+ rc = atread_submit(cs, BAS_TIMEOUT);
+ if (rc >= 0 || rc == -ENODEV)
+ /* resubmitted or disconnected */
+ /* - bypass regular exit block */
+ return;
+ error_reset(cs);
+ }
+ break;
+
+ case -ENOENT: /* cancelled */
+ case -ECONNRESET: /* cancelled (async) */
+ case -EINPROGRESS: /* pending */
+ case -ENODEV: /* device removed */
+ case -ESHUTDOWN: /* device shut down */
+ /* no action necessary */
+ gig_dbg(DEBUG_USBREQ, "%s: %s",
+ __func__, get_usb_statmsg(urb->status));
+ break;
+
+ default: /* severe trouble */
+ dev_warn(cs->dev, "control read: %s\n",
+ get_usb_statmsg(urb->status));
+ if (ucs->retry_cmd_in++ < BAS_RETRY) {
+ dev_notice(cs->dev, "control read: retry %d\n",
+ ucs->retry_cmd_in);
+ rc = atread_submit(cs, BAS_TIMEOUT);
+ if (rc >= 0 || rc == -ENODEV)
+ /* resubmitted or disconnected */
+ /* - bypass regular exit block */
+ return;
+ } else {
+ dev_err(cs->dev,
+ "control read: giving up after %d tries\n",
+ ucs->retry_cmd_in);
+ }
+ error_reset(cs);
+ }
+
+ kfree(ucs->rcvbuf);
+ ucs->rcvbuf = NULL;
+ ucs->rcvbuf_size = 0;
+ if (have_data) {
+ gig_dbg(DEBUG_INTR, "%s-->BH", __func__);
+ gigaset_schedule_event(cs);
+ }
+}
+