net: usb: raw-ip: Fix autopm / system suspend issues.

Add system suspend count and avoid urb activity during
system suspend.  Use async autopm to avoid deadlock with
system suspend.  Do not allocate rx urb's constantly -
allocate once upon init, free rx urb upon exit.

Bug 929408, 952748, 957354

Change-Id: I4ea050fc881528cf44d2039d42891e21c9df8c4e
Signed-off-by: Michael Hsu <mhsu@nvidia.com>
(cherry picked from commit 8bd7322127ccf6727d949f4bc1b2a4eac4b6814e)
Reviewed-on: http://git-master/r/95166
Reviewed-by: Vinayak Pane <vpane@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>

1 files changed, 146 insertions, 23 deletions

diff --git a/drivers/net/usb/raw_ip_net.c b/drivers/net/usb/raw_ip_net.c
index b8cc5fd8a1bd..1b3b89b3c274 100644
--- a/drivers/net/usb/raw_ip_net.c
+++ b/drivers/net/usb/raw_ip_net.c
@@ -67,8 +67,13 @@ module_param(usb_net_raw_ip_tx_debug, ulong, 0644);
 MODULE_PARM_DESC(usb_net_raw_ip_tx_debug, "usb net (raw-ip) - tx debug");
 
 struct baseband_usb {
+	/* semaphore between disconnect/suspend/resume */
+	struct semaphore sem;
+	/* instance */
 	int baseband_index;
+	/* network statistics */
 	struct net_device_stats stats;
+	/* usb context */
 	struct {
 		struct usb_driver *driver;
 		struct usb_device *device;
@@ -87,8 +92,11 @@ struct baseband_usb {
 		struct workqueue_struct *tx_workqueue;
 		struct work_struct tx_work;
 	} usb;
+	/* re-usable rx urb */
 	struct urb *urb_r;
 	void *buff;
+	/* suspend count */
+	int susp_count;
 };
 
 static struct baseband_usb *baseband_usb_net[MAX_INTFS] = { 0, 0, 0};
@@ -158,6 +166,11 @@ static void baseband_usb_driver_disconnect(struct usb_interface *intf)
 				baseband_usb_net[i]->usb.interface, intf);
 			continue;
 		}
+		/* acquire semaphore */
+		if (down_interruptible(&baseband_usb_net[i]->sem)) {
+			pr_err("%s: cannot acquire semaphore\n", __func__);
+			continue;
+		}
 		/* kill usb tx */
 		while ((urb = usb_get_from_anchor(&baseband_usb_net[i]->
 			usb.tx_urb_deferred)) != (struct urb *) 0) {
@@ -192,6 +205,8 @@ static void baseband_usb_driver_disconnect(struct usb_interface *intf)
 		/* mark interface as disconnected */
 		baseband_usb_net[i]->usb.interface
 			= (struct usb_interface *) 0;
+		/* release semaphore */
+		up(&baseband_usb_net[i]->sem);
 	}
 
 }
@@ -200,10 +215,14 @@ static void baseband_usb_driver_disconnect(struct usb_interface *intf)
 static int baseband_usb_driver_suspend(struct usb_interface *intf,
 	pm_message_t message)
 {
-	int i;
+	int i, susp_count;
 
 	pr_debug("%s intf %p\n", __func__, intf);
 
+	pr_debug("%s: cnt %d intf=%p &intf->dev=%p kobj=%s\n",
+			__func__, atomic_read(&intf->dev.power.usage_count),
+			intf, &intf->dev, kobject_name(&intf->dev.kobj));
+
 	for (i = 0; i < max_intfs; i++) {
 		pr_debug("[%d]\n", i);
 		if (!baseband_usb_net[i])
@@ -213,13 +232,47 @@ static int baseband_usb_driver_suspend(struct usb_interface *intf,
 				baseband_usb_net[i]->usb.interface, intf);
 			continue;
 		}
+		/* increment suspend count */
+		susp_count = (baseband_usb_net[i]->susp_count)++;
+		if (susp_count > 0) {
+			pr_debug("%s: susp_count %d > 0 (already suspended)\n",
+				__func__, susp_count);
+			continue;
+		}
+		if (susp_count < 0) {
+			pr_debug("%s: susp_count %d < 0 (ILLEGAL VALUE)\n",
+				__func__, susp_count);
+			baseband_usb_net[i]->susp_count = 0;
+			continue;
+		}
+		pr_debug("%s: susp_count = %d (suspending...)\n",
+			__func__, susp_count);
+		/* acquire semaphore */
+		if (down_interruptible(&baseband_usb_net[i]->sem)) {
+			pr_err("%s: cannot acquire semaphore\n", __func__);
+			continue;
+		}
 		/* kill usb rx */
 		if (!baseband_usb_net[i]->usb.rx_urb) {
 			pr_debug("rx_usb already killed\n");
+			up(&baseband_usb_net[i]->sem);
 			continue;
 		}
+		pr_debug("%s: kill rx_urb {\n",__func__);
 		usb_kill_urb(baseband_usb_net[i]->usb.rx_urb);
+		pr_debug("%s: kill rx_urb }\n",__func__);
 		baseband_usb_net[i]->usb.rx_urb = (struct urb *) 0;
+		/* cancel tx urb work (will restart after resume) */
+		if (!baseband_usb_net[i]->usb.tx_workqueue) {
+			pr_err("%s: !tx_workqueue\n", __func__);
+			up(&baseband_usb_net[i]->sem);
+			continue;
+		}
+		pr_debug("%s: cancel_work_sync {\n",__func__);
+		cancel_work_sync(&baseband_usb_net[i]->usb.tx_work);
+		pr_debug("%s: cancel_work_sync }\n",__func__);
+		/* release semaphore */
+		up(&baseband_usb_net[i]->sem);
 	}
 
 	return 0;
@@ -227,10 +280,14 @@ static int baseband_usb_driver_suspend(struct usb_interface *intf,
 
 static int baseband_usb_driver_resume(struct usb_interface *intf)
 {
-	int i, err;
+	int i, err, susp_count;
 
 	pr_debug("%s intf %p\n", __func__, intf);
 
+	pr_debug("%s: cnt %d intf=%p &intf->dev=%p kobj=%s\n",
+			__func__, atomic_read(&intf->dev.power.usage_count),
+			intf, &intf->dev, kobject_name(&intf->dev.kobj));
+
 	for (i = 0; i < max_intfs; i++) {
 		pr_debug("[%d]\n", i);
 		if (!baseband_usb_net[i])
@@ -240,16 +297,48 @@ static int baseband_usb_driver_resume(struct usb_interface *intf)
 				baseband_usb_net[i]->usb.interface, intf);
 			continue;
 		}
+		/* decrement suspend count */
+		susp_count = --(baseband_usb_net[i]->susp_count);
+		if (susp_count > 0) {
+			pr_debug("%s: susp_count %d > 0 (not resuming yet)\n",
+				__func__, susp_count);
+			continue;
+		}
+		if (susp_count < 0) {
+			pr_debug("%s: susp_count %d < 0 (ILLEGAL VALUE)\n",
+				__func__, susp_count);
+			baseband_usb_net[i]->susp_count = 0;
+			continue;
+		}
+		pr_debug("%s: susp_count = %d (resuming...)\n",
+			__func__, susp_count);
+		/* acquire semaphore */
+		if (down_interruptible(&baseband_usb_net[i]->sem)) {
+			pr_err("%s: cannot acquire semaphore\n", __func__);
+			continue;
+		}
 		/* start usb rx */
 		if (baseband_usb_net[i]->usb.rx_urb) {
 			pr_debug("rx_usb already exists\n");
+			up(&baseband_usb_net[i]->sem);
 			continue;
 		}
 		err = usb_net_raw_ip_rx_urb_submit(baseband_usb_net[i]);
 		if (err < 0) {
 			pr_err("submit rx failed - err %d\n", err);
+			up(&baseband_usb_net[i]->sem);
 			continue;
 		}
+		/* restart tx urb work (cancelled in suspend) */
+		if (!baseband_usb_net[i]->usb.tx_workqueue) {
+			pr_err("%s: !tx_workqueue\n", __func__);
+			up(&baseband_usb_net[i]->sem);
+			continue;
+		}
+		queue_work(baseband_usb_net[i]->usb.tx_workqueue,
+			&baseband_usb_net[i]->usb.tx_work);
+		/* release semaphore */
+		up(&baseband_usb_net[i]->sem);
 	}
 
 	return 0;
@@ -361,6 +450,9 @@ struct baseband_usb *baseband_usb_open(int index,
 	if (!usb)
 		return (struct baseband_usb *) 0;
 
+	/* create semaphores */
+	sema_init(&usb->sem, 1);
+
 	/* open usb driver */
 	sprintf(baseband_usb_driver_name[index],
 		"baseband_usb_%x_%x_%x",
@@ -424,6 +516,9 @@ void baseband_usb_close(struct baseband_usb *usb)
 		pr_debug("close usb driver }\n");
 	}
 
+	/* destroy semaphores */
+	memset(&usb->sem, 0, sizeof(usb->sem));
+
 	/* free baseband usb structure */
 	kfree(usb);
 
@@ -485,12 +580,22 @@ static netdev_tx_t baseband_usb_netdev_start_xmit(
 	}
 	usb = baseband_usb_net[i];
 
+	/* autoresume if suspended */
+	if (usb->usb.interface) {
+		usb_autopm_get_interface_async(usb->usb.interface);
+	} else {
+		pr_err("%s: tx get interface error\n", __func__);
+		netif_stop_queue(dev);
+		usb->stats.tx_errors++;
+		return NETDEV_TX_BUSY;
+	}
+
 	/* submit tx urb */
 	err = usb_net_raw_ip_tx_urb_submit(usb, skb);
 	if (err < 0) {
-		pr_err("tx urb submit error\n");
-		usb->stats.tx_errors++;
+		pr_err("%s: tx urb submit error\n", __func__);
 		netif_stop_queue(dev);
+		usb->stats.tx_errors++;
 		return NETDEV_TX_BUSY;
 	}
 
@@ -600,14 +705,15 @@ static void usb_net_raw_ip_rx_urb_comp(struct urb *urb)
 	switch (urb->status) {
 	case 0:
 		break;
-	case -ENOENT:
-		/* fall through */
 	case -ESHUTDOWN:
 		/* fall through */
-	case -EPROTO:
 		pr_info("%s: rx urb %p - link shutdown %d\n",
 			__func__, urb, urb->status);
 		goto err_exit;
+	case -EPROTO:
+		pr_info("%s: rx urb %p - link shutdown %d EPROTO\n",
+			__func__, urb, urb->status);
+		goto err_exit;
 	default:
 		pr_info("%s: rx urb %p - status %d\n",
 			__func__, urb, urb->status);
@@ -615,7 +721,7 @@ static void usb_net_raw_ip_rx_urb_comp(struct urb *urb)
 	}
 
 	/* put rx urb data in rx buffer */
-	if (urb->actual_length) {
+	if (urb->actual_length > 0) {
 		pr_debug("usb_net_raw_ip_rx_urb_comp - "
 			"urb->actual_length %d\n", urb->actual_length);
 		/* allocate skb with space for
@@ -664,6 +770,10 @@ static void usb_net_raw_ip_rx_urb_comp(struct urb *urb)
 	/* mark rx urb complete */
 	usb->usb.rx_urb = (struct urb *) 0;
 
+	/* do not submit urb if interface is suspending */
+	if (urb->status == -ENOENT)
+		return;
+
 	/* submit next rx urb */
 	usb_net_raw_ip_rx_urb_submit(usb);
 	return;
@@ -745,25 +855,28 @@ static int usb_net_raw_ip_tx_urb_submit(struct baseband_usb *usb,
 		pr_err("%s: !usb\n", __func__);
 		return -EINVAL;
 	}
-	if (!skb) {
-		pr_err("%s: !skb\n", __func__);
-		return -EINVAL;
-	}
 	if (!usb->usb.interface) {
 		pr_err("usb interface disconnected - not submitting tx urb\n");
 		return -EINVAL;
 	}
+	if (!skb) {
+		pr_err("%s: !skb\n", __func__);
+		usb_autopm_put_interface_async(usb->usb.interface);
+		return -EINVAL;
+	}
 
 	/* allocate urb */
 	urb = usb_alloc_urb(0, GFP_ATOMIC);
 	if (!urb) {
 		pr_err("usb_alloc_urb() failed\n");
+		usb_autopm_put_interface_async(usb->usb.interface);
 		return -ENOMEM;
 	}
 	buf = kzalloc(skb->len - 14, GFP_ATOMIC);
 	if (!buf) {
 		pr_err("usb buffer kzalloc() failed\n");
 		usb_free_urb(urb);
+		usb_autopm_put_interface_async(usb->usb.interface);
 		return -ENOMEM;
 	}
 	err = skb_copy_bits(skb, 14, buf, skb->len - 14);
@@ -771,6 +884,7 @@ static int usb_net_raw_ip_tx_urb_submit(struct baseband_usb *usb,
 		pr_err("skb_copy_bits() failed - %d\n", err);
 		kfree(buf);
 		usb_free_urb(urb);
+		usb_autopm_put_interface_async(usb->usb.interface);
 		return err;
 	}
 	usb_fill_bulk_urb(urb, usb->usb.device, usb->usb.pipe.bulk.out,
@@ -814,18 +928,23 @@ static void usb_net_raw_ip_tx_urb_work(struct work_struct *work)
 		return;
 	}
 
+	/* check if suspended */
+	if (usb->susp_count > 0) {
+		pr_info("%s: usb->susp_count %d > 0 (suspended)\n",
+			__func__, usb->susp_count);
+		return;
+	}
+
 	/* submit queued tx urb(s) */
 	while ((urb = usb_get_from_anchor(&usb->usb.tx_urb_deferred))
 		!= (struct urb *) 0) {
 		/* decrement count from usb_get_from_anchor() */
 		usb_free_urb(urb);
-
-		/* autoresume before tx */
-		usb_mark_last_busy(usb->usb.device);
-		err = usb_autopm_get_interface(usb->usb.interface);
-		if (err < 0) {
-			pr_err("%s: usb_autopm_get_interface(%p) failed %d\n",
-				__func__, usb->usb.interface, err);
+		/* check if usb interface disconnected */
+		if (!usb->usb.interface) {
+			pr_err("%s: not submitting tx urb %p"
+				" - interface disconnected\n",
+				__func__, urb);
 			if (urb->transfer_buffer) {
 				kfree(urb->transfer_buffer);
 				urb->transfer_buffer = (void *) 0;
@@ -834,17 +953,20 @@ static void usb_net_raw_ip_tx_urb_work(struct work_struct *work)
 			usb->stats.tx_errors++;
 			continue;
 		}
+		/* autoresume before tx */
+		usb_mark_last_busy(usb->usb.device);
 		/* submit tx urb */
 		err = usb_submit_urb(urb, GFP_ATOMIC);
 		if (err < 0) {
 			pr_err("%s: usb_submit_urb(%p) failed - err %d\n",
 				__func__, urb, err);
-			usb_autopm_put_interface(usb->usb.interface);
+			usb_autopm_put_interface_async(usb->usb.interface);
 			if (urb->transfer_buffer) {
 				kfree(urb->transfer_buffer);
 				urb->transfer_buffer = (void *) 0;
 			}
 			usb_free_urb(urb);
+			usb->stats.tx_errors++;
 			continue;
 		}
 		/* free tx urb
@@ -882,6 +1004,7 @@ static void usb_net_raw_ip_tx_urb_comp(struct urb *urb)
 	case -EPROTO:
 		pr_info("%s: tx urb %p - link shutdown %d\n",
 			__func__, urb, urb->status);
+		usb_autopm_put_interface_async(usb->usb.interface);
 		goto err_exit;
 	default:
 		pr_info("%s: tx urb %p - status %d\n",
@@ -894,6 +1017,7 @@ static void usb_net_raw_ip_tx_urb_comp(struct urb *urb)
 		usb->stats.tx_packets++;
 		usb->stats.tx_bytes += urb->transfer_buffer_length;
 	}
+
 	/* autosuspend after tx completed */
 	if (!usb->usb.interface) {
 		pr_err("%s: usb interface disconnected"
@@ -901,7 +1025,7 @@ static void usb_net_raw_ip_tx_urb_comp(struct urb *urb)
 			__func__);
 		goto err_exit;
 	}
-	usb_autopm_put_interface(usb->usb.interface);
+	usb_autopm_put_interface_async(usb->usb.interface);
 
 err_exit:
 	/* free tx urb transfer buffer */
@@ -909,7 +1033,6 @@ err_exit:
 		kfree(urb->transfer_buffer);
 		urb->transfer_buffer = (void *) 0;
 	}
-
 	pr_debug("usb_net_raw_ip_tx_urb_comp }\n");
 }
 
@@ -932,6 +1055,7 @@ static int usb_net_raw_ip_init(void)
 			err = -1;
 			goto error_exit;
 		}
+		init_usb_anchor(&baseband_usb_net[i]->usb.tx_urb_deferred);
 		/* register network device */
 		usb_net_raw_ip_dev[i] = alloc_netdev(0,
 			BASEBAND_USB_NET_DEV_NAME,
@@ -964,7 +1088,6 @@ static int usb_net_raw_ip_init(void)
 			goto error_exit;
 		}
 		/* start usb tx */
-		init_usb_anchor(&baseband_usb_net[i]->usb.tx_urb_deferred);
 		sprintf(name, "raw_ip_tx_wq-%d",
 			baseband_usb_net[i]->baseband_index);
 		baseband_usb_net[i]->usb.tx_workqueue