91	+static char printBuf[PRINTBUF_SIZE];

574	+static char printBuf[PRINTBUF_SIZE];

910	+static char printBuf[PRINTBUF_SIZE];

2390	+static char printBuf[PRINTBUF_SIZE];

Do we really need a global string? Would avoid calling clear.

1467	+ * $AOSP/hardware/ril/libril/ril.cpp
1468	+ */
1469	+#define startRequest sprintf(printBuf, "(")
1470	+#define closeRequest sprintf(printBuf, "%s)", printBuf)
1471	+#define printRequest(token, req) \
1472	+ ofono_debug("[%04d]> %s %s", token, ril_request_id_to_string(req), printBuf)
1473	+
1474	+#define startResponse sprintf(printBuf, "%s {", printBuf)
1475	+#define closeResponse sprintf(printBuf, "%s}", printBuf)
1476	+#define printResponse ofono_debug("%s", printBuf)
1477	+
1478	+#define clearPrintBuf printBuf[0] = 0
1479	+#define removeLastChar printBuf[strlen(printBuf)-1] = 0
1480	+#define appendPrintBuf(x...) sprintf(printBuf, x)

91	+static char printBuf[PRINTBUF_SIZE];

Coding style here might be an issue when pushing this code upstream. I'd guess it'd be better to use print_buf instead.

114	+ if (message->buf_len < 36) {
115	+ DBG("Parcel is less then minimum DataCallResponseV6 size!");

Missing "decode_ril_error(&error, "FAIL");".

126	+ /* TODO: make conditional */
127	+ appendPrintBuf("[%04d]< %s",
128	+ message->serial_no,
129	+ ril_request_id_to_string(message->req));
130	+ startResponse;
131	+ /* TODO: make conditional */

Mind moving this code a bit bellow so it can be near the rest of the append/close/print logic? Otherwise it's hard to track which message it's actually covering (in case of another message setup later).

135	+ /* RIL version */
136	+ version = parcel_r_int32(&rilp);
137	+
138	+ /* Size of call list */
139	+ /* TODO: What if there's more than 1 call in the list?? */
140	+ num = parcel_r_int32(&rilp);

Isn't the reply just a RIL_Data_Call_Response_v6 struct? If so, mind adding a comment saying that the version and num arguments were not described correctly by the Android ril.h file?

175	+ if (status != 0) {
176	+ DBG("Reply failure; status %d", status);
177	+ gcd->state = STATE_IDLE;
178	+ goto error;
179	+ }

203	+ if (ip_addrs[0] == NULL) {
204	+ DBG("Invalid IP address field returned: %s", raw_ip_addrs);
205	+ goto error;
206	+ }

217	+ if (split_ip_addr[0] == NULL) {
218	+ ofono_error("Invalid IP address; can't strip prefix: %s",
219	+ ip_addrs[0]);
220	+ goto error;
221	+ }

230	+ if (gateways[0] == NULL) {
231	+ DBG("Invalid gateways field returned: %s", raw_gws);
232	+ goto error;
233	+ }

Don't you also need to update error.error here?

Also, in case of error, we're not releasing any of the strings allocated with parcel_r_string (your code just free them in case it all works).

266	+ guchar profile[5] = { 0x00 };

Not used.

329	+ DBG("Invalid protocol");

Mind doing a better error message here? Otherwise it will be hard to get from the ofono log.

334	+ appendPrintBuf("%s %s,%s,%s,%s,%s,%s,%s",
335	+ printBuf,
336	+ tech,
337	+ DATA_PROFILE_DEFAULT,
338	+ ctx->apn,
339	+ ctx->username,
340	+ ctx->password,
341	+ CHAP_PAP_OK,
342	+ protocol);
343	+
344	+ ret = g_ril_send(gcd->ril,
345	+ request,
346	+ rilp.data,
347	+ rilp.size,
348	+ ril_setup_data_call_cb, cbd, g_free);
349	+
350	+ /* TODO: make conditional */
351	+ closeRequest;
352	+ printRequest(ret, request);
353	+ /* TODO: make conditional */

Mind containing all the printbuf related function calls together? Easier to read and understand.

375	+ appendPrintBuf("[%04d]< %s",
376	+ message->serial_no,
377	+ ril_request_id_to_string(message->req));

Why just the append without any clear, response or print?


720	+ if (cb)
721	+ cb(&error, status, cbd->data);
722	+ return;
723	+
724	+error:
725	+ if (cb)
726	+ cb(&error, -1, cbd->data);

Could probably simplify by setting up status in case of an error.