[PATCH v3 0/9] atm: propagate atm_dev signal carrier to LOWER_UP of netdevice

[PATCH v3 0/9] atm: propagate atm_dev signal carrier to LOWER_UP of netdevice

[Karl Hiramoto]

Changes from v2:
 * use atomic instead of blocking notifier
 * use read_lock_irq() instead of read_lock() in atm/br2684
 * clean up comments
 * remove unused variable.  I feel really bad about missing that last time.
 
Changes from v1:
Use atm_dev notifier chain  instead of callback function pointer in struct vcc.
In drivers/usb/atm call atm_dev_signal_change().

In userspace it's helpful to know if a network device has a carrier signal.
Often it is monitored via netlink.  This patchset allows a way for the
struct atm_dev drivers to pass carrier on/off to the netdevice.

For DSL, carrier is on when the line has reached showtime state.

Currently this patchset only propagates the changes to br2684 vccs,
as this is the only type of hardware I have to test.

If you prefer git you can pull from:
git://github.com/karlhiramoto/linux-2.6.git atm-v3

Karl Hiramoto (9):
  atm: propagate signal changes via notifier
  atm/br2684: register notifier event for carrier signal changes.
  atm/adummy: add syfs DEVICE_ATTR to change signal
  atm/idt77105.c: call atm_dev_signal_change() when signal changes.
  atm/solos-pci: call atm_dev_signal_change() when signal changes.
  atm/suni.c: call atm_dev_signal_change() when signal changes.
  usb/atm/cxacru.c: call atm_dev_signal_change() when signal changes.
  usb/atm/speedtch.c: call atm_dev_signal_change() when signal changes.
  usb/atm/ueagle-atm.c: call atm_dev_signal_change() when signal
    changes.

 drivers/atm/adummy.c         |   39 ++++++++++++++++++++++++
 drivers/atm/idt77105.c       |   11 ++++---
 drivers/atm/solos-pci.c      |    6 ++--
 drivers/atm/suni.c           |    5 ++-
 drivers/usb/atm/cxacru.c     |   18 ++++++------
 drivers/usb/atm/speedtch.c   |   10 +++---
 drivers/usb/atm/ueagle-atm.c |   13 ++++++--
 include/linux/atmdev.h       |   19 ++++++++++++
 net/atm/br2684.c             |   66 ++++++++++++++++++++++++++++++++++++++++-
 net/atm/common.c             |   30 +++++++++++++++++++
 10 files changed, 188 insertions(+), 29 deletions(-)

[PATCH v3 1/9] atm: propagate signal changes via notifier

[Karl Hiramoto]

Add notifier chain for changes in atm_dev.

Clients like br2684 will call register_atmdevice_notifier() to be notified of
changes. Drivers will call atm_dev_signal_change() to notify clients like
br2684 of the change.

On DSL and ATM devices it's usefull to have a know if you have a carrier
signal. netdevice LOWER_UP changes can be propagated to userspace via netlink
monitor.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 include/linux/atmdev.h |   19 +++++++++++++++++++
 net/atm/common.c       |   30 ++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 0 deletions(-)

diff --git a/include/linux/atmdev.h b/include/linux/atmdev.h
index 817b237..7c6dfd3 100644
--- a/include/linux/atmdev.h
+++ b/include/linux/atmdev.h
@@ -431,6 +431,15 @@ struct atm_dev *atm_dev_register(const char *type,const struct atmdev_ops *ops,
     int number,unsigned long *flags); /* number == -1: pick first available */
 struct atm_dev *atm_dev_lookup(int number);
 void atm_dev_deregister(struct atm_dev *dev);
+
+/**
+* atm_dev_signal_change
+*
+* Propagate lower layer signal change in atm_dev->signal to netdevice.
+* The event will be sent via a notifier call chain.
+*/
+void atm_dev_signal_change(struct atm_dev *dev, char signal);
+
 void vcc_insert_socket(struct sock *sk);
 
 
@@ -510,6 +519,16 @@ void register_atm_ioctl(struct atm_ioctl *);
  */
 void deregister_atm_ioctl(struct atm_ioctl *);
 
+
+/**
+* register_atmdevice_notifier - register atm_dev notify events
+*
+* Clients like br2684 will register notify events
+* Currently we notify of signal found/lost
+*/
+int register_atmdevice_notifier(struct notifier_block *nb);
+void unregister_atmdevice_notifier(struct notifier_block *nb);
+
 #endif /* __KERNEL__ */
 
 #endif
diff --git a/net/atm/common.c b/net/atm/common.c
index b43feb1..940404a 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -37,6 +37,8 @@ EXPORT_SYMBOL(vcc_hash);
 DEFINE_RWLOCK(vcc_sklist_lock);
 EXPORT_SYMBOL(vcc_sklist_lock);
 
+static ATOMIC_NOTIFIER_HEAD(atm_dev_notify_chain);
+
 static void __vcc_insert_socket(struct sock *sk)
 {
 	struct atm_vcc *vcc = atm_sk(sk);
@@ -212,6 +214,22 @@ void vcc_release_async(struct atm_vcc *vcc, int reply)
 }
 EXPORT_SYMBOL(vcc_release_async);
 
+void atm_dev_signal_change(struct atm_dev *dev, char signal)
+{
+	pr_debug("%s signal=%d dev=%p number=%d dev->signal=%d\n",
+		__func__, signal, dev, dev->number, dev->signal);
+
+	/* atm driver sending invalid signal */
+	WARN_ON(signal < ATM_PHY_SIG_LOST || signal > ATM_PHY_SIG_FOUND);
+
+	if (dev->signal == signal)
+		return; /* no change */
+
+	dev->signal = signal;
+
+	atomic_notifier_call_chain(&atm_dev_notify_chain, signal, dev);
+}
+EXPORT_SYMBOL(atm_dev_signal_change);
 
 void atm_dev_release_vccs(struct atm_dev *dev)
 {
@@ -781,6 +799,18 @@ int vcc_getsockopt(struct socket *sock, int level, int optname,
 	return vcc->dev->ops->getsockopt(vcc, level, optname, optval, len);
 }
 
+int register_atmdevice_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&atm_dev_notify_chain, nb);
+}
+EXPORT_SYMBOL_GPL(register_atmdevice_notifier);
+
+void unregister_atmdevice_notifier(struct notifier_block *nb)
+{
+	atomic_notifier_chain_unregister(&atm_dev_notify_chain, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_atmdevice_notifier);
+
 static int __init atm_init(void)
 {
 	int error;
-- 
1.7.1

[PATCH v3 2/9] atm/br2684: register notifier event for carrier signal changes.

[Karl Hiramoto]

When a signal change event occurs call netif_carrier_on/off.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 net/atm/br2684.c |   66 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 64 insertions(+), 2 deletions(-)

diff --git a/net/atm/br2684.c b/net/atm/br2684.c
index 6719af6..01a628d 100644
--- a/net/atm/br2684.c
+++ b/net/atm/br2684.c
@@ -139,6 +139,42 @@ static struct net_device *br2684_find_dev(const struct br2684_if_spec *s)
 	return NULL;
 }
 
+static int atm_dev_event(struct notifier_block *this, unsigned long event,
+		 void *arg)
+{
+	struct atm_dev *atm_dev = arg;
+	struct list_head *lh;
+	struct net_device *net_dev;
+	struct br2684_vcc *brvcc;
+	struct atm_vcc *atm_vcc;
+
+	pr_debug("event=%ld dev=%p\n", event, atm_dev);
+
+	read_lock_irq(&devs_lock);
+	list_for_each(lh, &br2684_devs) {
+		net_dev = list_entry_brdev(lh);
+
+		list_for_each_entry(brvcc, &BRPRIV(net_dev)->brvccs, brvccs) {
+			atm_vcc = brvcc->atmvcc;
+			if (atm_vcc && brvcc->atmvcc->dev == atm_dev) {
+
+				if (atm_vcc->dev->signal == ATM_PHY_SIG_LOST)
+					netif_carrier_off(net_dev);
+				else
+					netif_carrier_on(net_dev);
+
+			}
+		}
+	}
+	read_unlock_irq(&devs_lock);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block atm_dev_notifier = {
+	.notifier_call = atm_dev_event,
+};
+
 /* chained vcc->pop function.  Check if we should wake the netif_queue */
 static void br2684_pop(struct atm_vcc *vcc, struct sk_buff *skb)
 {
@@ -362,6 +398,12 @@ static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
 			unregister_netdev(net_dev);
 			free_netdev(net_dev);
 		}
+		read_lock_irq(&devs_lock);
+		if (list_empty(&br2684_devs)) {
+			/* last br2684 device */
+			unregister_atmdevice_notifier(&atm_dev_notifier);
+		}
+		read_unlock_irq(&devs_lock);
 		return;
 	}
 
@@ -530,6 +572,13 @@ static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
 
 		br2684_push(atmvcc, skb);
 	}
+
+	/* initialize netdev carrier state */
+	if (atmvcc->dev->signal == ATM_PHY_SIG_LOST)
+		netif_carrier_off(net_dev);
+	else
+		netif_carrier_on(net_dev);
+
 	__module_get(THIS_MODULE);
 	return 0;
 
@@ -620,9 +669,16 @@ static int br2684_create(void __user *arg)
 	}
 
 	write_lock_irq(&devs_lock);
+
 	brdev->payload = payload;
-	brdev->number = list_empty(&br2684_devs) ? 1 :
-	    BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
+
+	if (list_empty(&br2684_devs)) {
+		/* 1st br2684 device */
+		register_atmdevice_notifier(&atm_dev_notifier);
+		brdev->number = 1;
+	} else
+		brdev->number = BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
+
 	list_add_tail(&brdev->br2684_devs, &br2684_devs);
 	write_unlock_irq(&devs_lock);
 	return 0;
@@ -758,6 +814,7 @@ static int __init br2684_init(void)
 		return -ENOMEM;
 #endif
 	register_atm_ioctl(&br2684_ioctl_ops);
+
 	return 0;
 }
 
@@ -772,6 +829,11 @@ static void __exit br2684_exit(void)
 	remove_proc_entry("br2684", atm_proc_root);
 #endif
 
+
+	/* if not already empty */
+	if (!list_empty(&br2684_devs))
+		unregister_atmdevice_notifier(&atm_dev_notifier);
+
 	while (!list_empty(&br2684_devs)) {
 		net_dev = list_entry_brdev(br2684_devs.next);
 		brdev = BRPRIV(net_dev);
-- 
1.7.1

[PATCH v3 3/9] atm/adummy: add syfs DEVICE_ATTR to change signal

[Karl Hiramoto]

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 drivers/atm/adummy.c |   39 +++++++++++++++++++++++++++++++++++++++
 1 files changed, 39 insertions(+), 0 deletions(-)

diff --git a/drivers/atm/adummy.c b/drivers/atm/adummy.c
index 6d44f07..46b9476 100644
--- a/drivers/atm/adummy.c
+++ b/drivers/atm/adummy.c
@@ -40,6 +40,42 @@ struct adummy_dev {
 
 static LIST_HEAD(adummy_devs);
 
+static ssize_t __set_signal(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf, size_t len)
+{
+	struct atm_dev *atm_dev = container_of(dev, struct atm_dev, class_dev);
+	int signal;
+
+	if (sscanf(buf, "%d", &signal) == 1) {
+
+		if (signal < ATM_PHY_SIG_LOST || signal > ATM_PHY_SIG_FOUND)
+			signal = ATM_PHY_SIG_UNKNOWN;
+
+		atm_dev_signal_change(atm_dev, signal);
+		return 1;
+	}
+	return -EINVAL;
+}
+
+static ssize_t __show_signal(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct atm_dev *atm_dev = container_of(dev, struct atm_dev, class_dev);
+	return sprintf(buf, "%d\n", atm_dev->signal);
+}
+static DEVICE_ATTR(signal, 0644, __show_signal, __set_signal);
+
+static struct attribute *adummy_attrs[] = {
+	&dev_attr_signal.attr,
+	NULL
+};
+
+static struct attribute_group adummy_group_attrs = {
+	.name = NULL, /* We want them in dev's root folder */
+	.attrs = adummy_attrs
+};
+
 static int __init
 adummy_start(struct atm_dev *dev)
 {
@@ -128,6 +164,9 @@ static int __init adummy_init(void)
 	adummy_dev->atm_dev = atm_dev;
 	atm_dev->dev_data = adummy_dev;
 
+	if (sysfs_create_group(&atm_dev->class_dev.kobj, &adummy_group_attrs))
+		dev_err(&atm_dev->class_dev, "Could not register attrs for adummy\n");
+
 	if (adummy_start(atm_dev)) {
 		printk(KERN_ERR DEV_LABEL ": adummy_start() failed\n");
 		err = -ENODEV;
-- 
1.7.1

[PATCH v3 4/9] atm/idt77105.c: call atm_dev_signal_change() when signal changes.

[Karl Hiramoto]

Propagate changes to upper atm layer.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 drivers/atm/idt77105.c |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/atm/idt77105.c b/drivers/atm/idt77105.c
index dab5cf5..bca9cb8 100644
--- a/drivers/atm/idt77105.c
+++ b/drivers/atm/idt77105.c
@@ -126,7 +126,7 @@ static void idt77105_restart_timer_func(unsigned long dummy)
                 istat = GET(ISTAT); /* side effect: clears all interrupt status bits */
                 if (istat & IDT77105_ISTAT_GOODSIG) {
                     /* Found signal again */
-                    dev->signal = ATM_PHY_SIG_FOUND;
+                    atm_dev_signal_change(dev, ATM_PHY_SIG_FOUND);
 	            printk(KERN_NOTICE "%s(itf %d): signal detected again\n",
                         dev->type,dev->number);
                     /* flush the receive FIFO */
@@ -222,7 +222,7 @@ static void idt77105_int(struct atm_dev *dev)
             /* Rx Signal Condition Change - line went up or down */
             if (istat & IDT77105_ISTAT_GOODSIG) {   /* signal detected again */
                 /* This should not happen (restart timer does it) but JIC */
-                dev->signal = ATM_PHY_SIG_FOUND;
+		atm_dev_signal_change(dev, ATM_PHY_SIG_FOUND);
             } else {    /* signal lost */
                 /*
                  * Disable interrupts and stop all transmission and
@@ -235,7 +235,7 @@ static void idt77105_int(struct atm_dev *dev)
                     IDT77105_MCR_DRIC|
                     IDT77105_MCR_HALTTX
                     ) & ~IDT77105_MCR_EIP, MCR);
-                dev->signal = ATM_PHY_SIG_LOST;
+		atm_dev_signal_change(dev, ATM_PHY_SIG_LOST);
 	        printk(KERN_NOTICE "%s(itf %d): signal lost\n",
                     dev->type,dev->number);
             }
@@ -272,8 +272,9 @@ static int idt77105_start(struct atm_dev *dev)
 	memset(&PRIV(dev)->stats,0,sizeof(struct idt77105_stats));
         
         /* initialise dev->signal from Good Signal Bit */
-        dev->signal = GET(ISTAT) & IDT77105_ISTAT_GOODSIG ? ATM_PHY_SIG_FOUND :
-	  ATM_PHY_SIG_LOST;
+	atm_dev_signal_change(dev,
+		GET(ISTAT) & IDT77105_ISTAT_GOODSIG ?
+		ATM_PHY_SIG_FOUND : ATM_PHY_SIG_LOST);
 	if (dev->signal == ATM_PHY_SIG_LOST)
 		printk(KERN_WARNING "%s(itf %d): no signal\n",dev->type,
 		    dev->number);
-- 
1.7.1

[PATCH v3 5/9] atm/solos-pci: call atm_dev_signal_change() when signal changes.

[Karl Hiramoto]

Propagate changes to upper atm layer, so userspace netmontor knows when DSL
showtime reached.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 drivers/atm/solos-pci.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
index ded76c4..6174965 100644
--- a/drivers/atm/solos-pci.c
+++ b/drivers/atm/solos-pci.c
@@ -383,7 +383,7 @@ static int process_status(struct solos_card *card, int port, struct sk_buff *skb
 
 	/* Anything but 'Showtime' is down */
 	if (strcmp(state_str, "Showtime")) {
-		card->atmdev[port]->signal = ATM_PHY_SIG_LOST;
+		atm_dev_signal_change(card->atmdev[port], ATM_PHY_SIG_LOST);
 		release_vccs(card->atmdev[port]);
 		dev_info(&card->dev->dev, "Port %d: %s\n", port, state_str);
 		return 0;
@@ -401,7 +401,7 @@ static int process_status(struct solos_card *card, int port, struct sk_buff *skb
 		 snr[0]?", SNR ":"", snr, attn[0]?", Attn ":"", attn);
 	
 	card->atmdev[port]->link_rate = rate_down / 424;
-	card->atmdev[port]->signal = ATM_PHY_SIG_FOUND;
+	atm_dev_signal_change(card->atmdev[port], ATM_PHY_SIG_FOUND);
 
 	return 0;
 }
@@ -1246,7 +1246,7 @@ static int atm_init(struct solos_card *card)
 		card->atmdev[i]->ci_range.vci_bits = 16;
 		card->atmdev[i]->dev_data = card;
 		card->atmdev[i]->phy_data = (void *)(unsigned long)i;
-		card->atmdev[i]->signal = ATM_PHY_SIG_UNKNOWN;
+		atm_dev_signal_change(card->atmdev[i], ATM_PHY_SIG_UNKNOWN);
 
 		skb = alloc_skb(sizeof(*header), GFP_ATOMIC);
 		if (!skb) {
-- 
1.7.1

[PATCH v3 6/9] atm/suni.c: call atm_dev_signal_change() when signal changes.

[Karl Hiramoto]

Propagate changes to upper atm layer.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 drivers/atm/suni.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/atm/suni.c b/drivers/atm/suni.c
index da4b91f..41c56ea 100644
--- a/drivers/atm/suni.c
+++ b/drivers/atm/suni.c
@@ -291,8 +291,9 @@ static int suni_ioctl(struct atm_dev *dev,unsigned int cmd,void __user *arg)
 
 static void poll_los(struct atm_dev *dev)
 {
-	dev->signal = GET(RSOP_SIS) & SUNI_RSOP_SIS_LOSV ? ATM_PHY_SIG_LOST :
-	  ATM_PHY_SIG_FOUND;
+	atm_dev_signal_change(dev,
+		GET(RSOP_SIS) & SUNI_RSOP_SIS_LOSV ?
+		ATM_PHY_SIG_LOST : ATM_PHY_SIG_FOUND);
 }
 
 
-- 
1.7.1

[PATCH v3 7/9] usb/atm/cxacru.c: call atm_dev_signal_change() when signal changes.

[Karl Hiramoto]

Propagate signal changes to upper atm layer.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 drivers/usb/atm/cxacru.c |   18 +++++++++---------
 1 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/atm/cxacru.c b/drivers/usb/atm/cxacru.c
index c89990f..101ffc9 100644
--- a/drivers/usb/atm/cxacru.c
+++ b/drivers/usb/atm/cxacru.c
@@ -866,50 +866,50 @@ static void cxacru_poll_status(struct work_struct *work)
 	instance->line_status = buf[CXINF_LINE_STATUS];
 	switch (instance->line_status) {
 	case 0:
-		atm_dev->signal = ATM_PHY_SIG_LOST;
+		atm_dev_signal_change(atm_dev, ATM_PHY_SIG_LOST);
 		atm_info(usbatm, "ADSL line: down\n");
 		break;
 
 	case 1:
-		atm_dev->signal = ATM_PHY_SIG_LOST;
+		atm_dev_signal_change(atm_dev, ATM_PHY_SIG_LOST);
 		atm_info(usbatm, "ADSL line: attempting to activate\n");
 		break;
 
 	case 2:
-		atm_dev->signal = ATM_PHY_SIG_LOST;
+		atm_dev_signal_change(atm_dev, ATM_PHY_SIG_LOST);
 		atm_info(usbatm, "ADSL line: training\n");
 		break;
 
 	case 3:
-		atm_dev->signal = ATM_PHY_SIG_LOST;
+		atm_dev_signal_change(atm_dev, ATM_PHY_SIG_LOST);
 		atm_info(usbatm, "ADSL line: channel analysis\n");
 		break;
 
 	case 4:
-		atm_dev->signal = ATM_PHY_SIG_LOST;
+		atm_dev_signal_change(atm_dev, ATM_PHY_SIG_LOST);
 		atm_info(usbatm, "ADSL line: exchange\n");
 		break;
 
 	case 5:
 		atm_dev->link_rate = buf[CXINF_DOWNSTREAM_RATE] * 1000 / 424;
-		atm_dev->signal = ATM_PHY_SIG_FOUND;
+		atm_dev_signal_change(atm_dev, ATM_PHY_SIG_FOUND);
 
 		atm_info(usbatm, "ADSL line: up (%d kb/s down | %d kb/s up)\n",
 		     buf[CXINF_DOWNSTREAM_RATE], buf[CXINF_UPSTREAM_RATE]);
 		break;
 
 	case 6:
-		atm_dev->signal = ATM_PHY_SIG_LOST;
+		atm_dev_signal_change(atm_dev, ATM_PHY_SIG_LOST);
 		atm_info(usbatm, "ADSL line: waiting\n");
 		break;
 
 	case 7:
-		atm_dev->signal = ATM_PHY_SIG_LOST;
+		atm_dev_signal_change(atm_dev, ATM_PHY_SIG_LOST);
 		atm_info(usbatm, "ADSL line: initializing\n");
 		break;
 
 	default:
-		atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
+		atm_dev_signal_change(atm_dev, ATM_PHY_SIG_UNKNOWN);
 		atm_info(usbatm, "Unknown line state %02x\n", instance->line_status);
 		break;
 	}
-- 
1.7.1

[PATCH v3 8/9] usb/atm/speedtch.c: call atm_dev_signal_change() when signal changes.

[Karl Hiramoto]

Propagate signal changes to upper atm layer.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 drivers/usb/atm/speedtch.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/atm/speedtch.c b/drivers/usb/atm/speedtch.c
index 1335456..80f9617 100644
--- a/drivers/usb/atm/speedtch.c
+++ b/drivers/usb/atm/speedtch.c
@@ -525,7 +525,7 @@ static void speedtch_check_status(struct work_struct *work)
 
 		switch (status) {
 		case 0:
-			atm_dev->signal = ATM_PHY_SIG_LOST;
+			atm_dev_signal_change(atm_dev, ATM_PHY_SIG_LOST);
 			if (instance->last_status)
 				atm_info(usbatm, "ADSL line is down\n");
 			/* It may never resync again unless we ask it to... */
@@ -533,12 +533,12 @@ static void speedtch_check_status(struct work_struct *work)
 			break;
 
 		case 0x08:
-			atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
+			atm_dev_signal_change(atm_dev, ATM_PHY_SIG_UNKNOWN);
 			atm_info(usbatm, "ADSL line is blocked?\n");
 			break;
 
 		case 0x10:
-			atm_dev->signal = ATM_PHY_SIG_LOST;
+			atm_dev_signal_change(atm_dev, ATM_PHY_SIG_LOST);
 			atm_info(usbatm, "ADSL line is synchronising\n");
 			break;
 
@@ -554,7 +554,7 @@ static void speedtch_check_status(struct work_struct *work)
 			}
 
 			atm_dev->link_rate = down_speed * 1000 / 424;
-			atm_dev->signal = ATM_PHY_SIG_FOUND;
+			atm_dev_signal_change(atm_dev, ATM_PHY_SIG_FOUND);
 
 			atm_info(usbatm,
 				 "ADSL line is up (%d kb/s down | %d kb/s up)\n",
@@ -562,7 +562,7 @@ static void speedtch_check_status(struct work_struct *work)
 			break;
 
 		default:
-			atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
+			atm_dev_signal_change(atm_dev, ATM_PHY_SIG_UNKNOWN);
 			atm_info(usbatm, "unknown line state %02x\n", status);
 			break;
 		}
-- 
1.7.1

[PATCH v3 9/9] usb/atm/ueagle-atm.c: call atm_dev_signal_change() when signal changes.

[Karl Hiramoto]

Propagate signal changes to upper atm layer.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
---
 drivers/usb/atm/ueagle-atm.c |   13 ++++++++++---
 1 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/atm/ueagle-atm.c b/drivers/usb/atm/ueagle-atm.c
index e213d3f..ebae944 100644
--- a/drivers/usb/atm/ueagle-atm.c
+++ b/drivers/usb/atm/ueagle-atm.c
@@ -575,6 +575,13 @@ MODULE_PARM_DESC(annex,
 			sc->usbatm->atm_dev->type = val; \
 	} while (0)
 
+#define UPDATE_ATM_SIGNAL(val) \
+	do { \
+		if (sc->usbatm->atm_dev) \
+			atm_dev_signal_change(sc->usbatm->atm_dev, val); \
+	} while (0)
+
+
 /* Firmware loading */
 #define LOAD_INTERNAL     0xA0
 #define F8051_USBCS       0x7f92
@@ -1359,7 +1366,7 @@ static int uea_stat_e1(struct uea_softc *sc)
 	/* always update it as atm layer could not be init when we switch to
 	 * operational state
 	 */
-	UPDATE_ATM_STAT(signal, ATM_PHY_SIG_FOUND);
+	UPDATE_ATM_SIGNAL(ATM_PHY_SIG_FOUND);
 
 	/* wake up processes waiting for synchronization */
 	wake_up(&sc->sync_q);
@@ -1498,7 +1505,7 @@ static int uea_stat_e4(struct uea_softc *sc)
 	/* always update it as atm layer could not be init when we switch to
 	 * operational state
 	 */
-	UPDATE_ATM_STAT(signal, ATM_PHY_SIG_FOUND);
+	UPDATE_ATM_SIGNAL(ATM_PHY_SIG_FOUND);
 
 	/* wake up processes waiting for synchronization */
 	wake_up(&sc->sync_q);
@@ -1825,7 +1832,7 @@ static int uea_start_reset(struct uea_softc *sc)
 	 * So we will failed to wait Ready CMV.
 	 */
 	sc->cmv_ack = 0;
-	UPDATE_ATM_STAT(signal, ATM_PHY_SIG_LOST);
+	UPDATE_ATM_SIGNAL(ATM_PHY_SIG_LOST);
 
 	/* reset statistics */
 	memset(&sc->stats, 0, sizeof(struct uea_stats));
-- 
1.7.1

Re: [PATCH v3 0/9] atm: propagate atm_dev signal carrier to LOWER_UP of netdevice

[David Miller]

From: Karl Hiramoto <karl@hiramoto.org>
Date: Wed,  7 Jul 2010 10:50:27 +0200

> Changes from v2:
>  * use atomic instead of blocking notifier
>  * use read_lock_irq() instead of read_lock() in atm/br2684
>  * clean up comments
>  * remove unused variable.  I feel really bad about missing that last time.
>  
> Changes from v1:
> Use atm_dev notifier chain  instead of callback function pointer in struct vcc.
> In drivers/usb/atm call atm_dev_signal_change().
> 
> In userspace it's helpful to know if a network device has a carrier signal.
> Often it is monitored via netlink.  This patchset allows a way for the
> struct atm_dev drivers to pass carrier on/off to the netdevice.
> 
> For DSL, carrier is on when the line has reached showtime state.
> 
> Currently this patchset only propagates the changes to br2684 vccs,
> as this is the only type of hardware I have to test.
> 
> If you prefer git you can pull from:
> git://github.com/karlhiramoto/linux-2.6.git atm-v3

I think the locking still needs another tweak.

By using read_lock_irq() you are assuming that you are invoked
from a context where irqs are disabled.

That's not necessarily the case, in fact some of your notifier call
sites in the drivers are in interrupt handlers where interrupts may or
may not be disabled.

So you'll likely need to use read_lock_irqsave() and read_lock_irqrestore().

Next, please format comments:

/* Like
 * this.
 */

Thanks.