misc: samsung_modemctl: add timeouts to deal with modem crashes

In the event the modem is not responsive during boot, ramdump, or
semaphore acquisition, we timeout and return an error to userspace,
so the RIL can reset the modem.

Signed-off-by: Brian Swetland <swetland@google.com>

drivers/misc/samsung_modemctl/modem_ctl.c

@@ -132,11 +132,18 @@ static int mmio_owner_p(struct modemctl *mc)
 
 int modem_acquire_mmio(struct modemctl *mc)
 {
-	if (modem_request_mmio(mc) == 0)
-		if (wait_event_interruptible(mc->wq, mmio_owner_p(mc))) {
+	if (modem_request_mmio(mc) == 0) {
+		int ret = wait_event_interruptible_timeout(
+			mc->wq, mmio_owner_p(mc), 5 * HZ);
+		if (ret == 0) {
+			pr_err("modem_acquire_mmio() TIMEOUT\n");
+			return -ENODEV;
+		}
+		if (ret < 0) {
 			modem_release_mmio(mc, 0);
 			return -ERESTARTSYS;
 		}
+	}
 	if (!modem_running(mc)) {
 		modem_release_mmio(mc, 0);
 		return -ENODEV;
@@ -205,7 +212,7 @@ static ssize_t modemctl_read(struct file *filp, char __user *buf,
 			pr_info("[MODEM] requesting more ram\n");
 			writel(0, mc->mmio + OFF_SEM);
 			writel(MODEM_CMD_RAMDUMP_MORE, mc->mmio + OFF_MBOX_AP);
-			wait_event(mc->wq, mc->ramdump_size != 0); /* TODO: timeout */
+			wait_event_timeout(mc->wq, mc->ramdump_size != 0, 10 * HZ);
 		} else {
 			pr_info("[MODEM] no more ram to dump\n");
 			mc->ramdump_size = 0;
@@ -275,6 +282,8 @@ static ssize_t modemctl_write(struct file *filp, const char __user *buf,
 
 static int modem_start(struct modemctl *mc, int ramdump)
 {
+	int ret;
+
 	pr_info("[MODEM] modem_start() %s\n",
 		ramdump ? "ramdump" : "normal");
 
@@ -300,17 +309,18 @@ static int modem_start(struct modemctl *mc, int ramdump)
 		mc->ramdump_pos = 0;
 		writel(MODEM_CMD_RAMDUMP_START, mc->mmio + OFF_MBOX_AP);
 
-		/* TODO: timeout and fail */
-		wait_event(mc->wq, mc->status == MODEM_DUMPING);
+		ret = wait_event_timeout(mc->wq, mc->status == MODEM_DUMPING, 25 * HZ);
+		if (ret == 0)
+			return -ENODEV;
 	} else {
 		mc->status = MODEM_BOOTING_NORMAL;
 		writel(MODEM_CMD_BINARY_LOAD, mc->mmio + OFF_MBOX_AP);
 
-		/* TODO: timeout and fail */
-		wait_event(mc->wq, modem_running(mc));
+		ret = wait_event_timeout(mc->wq, modem_running(mc), 25 * HZ);
+		if (ret == 0)
+			return -ENODEV;
 	}
 
-
 	pr_info("[MODEM] modem_start() DONE\n");
 	return 0;
 }

drivers/misc/samsung_modemctl/modem_io.c

@@ -235,10 +235,13 @@ static int modem_pipe_send(struct m_pipe *pipe, struct modem_io *io)
 		MODEM_COUNT(pipe->mc, pipe_tx_delayed);
 		modem_release_mmio(pipe->mc, 0);
 
-		ret = wait_event_interruptible(pipe->mc->wq,
-					       (pipe->tx->avail >= size)
-					       || modem_offline(pipe->mc));
-		if (ret)
+		ret = wait_event_interruptible_timeout(
+			pipe->mc->wq,
+			(pipe->tx->avail >= size) || modem_offline(pipe->mc),
+			5 * HZ);
+		if (ret == 0)
+			return -ENODEV;
+		if (ret < 0)
 			return ret;
 	}
 }