From 0a1af6dfa0772ffedaef422127f1338fa0ddfed3 Mon Sep 17 00:00:00 2001 From: Elson Roy Serrao Date: Fri, 24 Mar 2023 14:48:02 -0700 Subject: [PATCH] usb: gadget: f_ecm: Add suspend/resume and remote wakeup support When host sends suspend notification to the device, handle the suspend callbacks in the function driver. Depending on the remote wakeup capability the device can either trigger a remote wakeup or wait for the host initiated resume to resume data transfer. Signed-off-by: Elson Roy Serrao Reviewed-by: Thinh Nguyen Link: https://lore.kernel.org/r/1679694482-16430-7-git-send-email-quic_eserrao@quicinc.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/f_ecm.c | 22 ++++++++++++ drivers/usb/gadget/function/u_ether.c | 63 +++++++++++++++++++++++++++++++++++ drivers/usb/gadget/function/u_ether.h | 4 +++ 3 files changed, 89 insertions(+) diff --git a/drivers/usb/gadget/function/f_ecm.c b/drivers/usb/gadget/function/f_ecm.c index a7ab30e..c6e63ad 100644 --- a/drivers/usb/gadget/function/f_ecm.c +++ b/drivers/usb/gadget/function/f_ecm.c @@ -885,6 +885,26 @@ static struct usb_function_instance *ecm_alloc_inst(void) return &opts->func_inst; } +static void ecm_suspend(struct usb_function *f) +{ + struct f_ecm *ecm = func_to_ecm(f); + struct usb_composite_dev *cdev = ecm->port.func.config->cdev; + + DBG(cdev, "ECM Suspend\n"); + + gether_suspend(&ecm->port); +} + +static void ecm_resume(struct usb_function *f) +{ + struct f_ecm *ecm = func_to_ecm(f); + struct usb_composite_dev *cdev = ecm->port.func.config->cdev; + + DBG(cdev, "ECM Resume\n"); + + gether_resume(&ecm->port); +} + static void ecm_free(struct usb_function *f) { struct f_ecm *ecm; @@ -952,6 +972,8 @@ static struct usb_function *ecm_alloc(struct usb_function_instance *fi) ecm->port.func.setup = ecm_setup; ecm->port.func.disable = ecm_disable; ecm->port.func.free_func = ecm_free; + ecm->port.func.suspend = ecm_suspend; + ecm->port.func.resume = ecm_resume; return &ecm->port.func; } diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c index f259975..6956ad8 100644 --- a/drivers/usb/gadget/function/u_ether.c +++ b/drivers/usb/gadget/function/u_ether.c @@ -437,6 +437,20 @@ static inline int is_promisc(u16 cdc_filter) return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS; } +static int ether_wakeup_host(struct gether *port) +{ + int ret; + struct usb_function *func = &port->func; + struct usb_gadget *gadget = func->config->cdev->gadget; + + if (func->func_suspended) + ret = usb_func_wakeup(func); + else + ret = usb_gadget_wakeup(gadget); + + return ret; +} + static netdev_tx_t eth_start_xmit(struct sk_buff *skb, struct net_device *net) { @@ -456,6 +470,15 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb, in = NULL; cdc_filter = 0; } + + if (dev->port_usb && dev->port_usb->is_suspend) { + DBG(dev, "Port suspended. Triggering wakeup\n"); + netif_stop_queue(net); + spin_unlock_irqrestore(&dev->lock, flags); + ether_wakeup_host(dev->port_usb); + return NETDEV_TX_BUSY; + } + spin_unlock_irqrestore(&dev->lock, flags); if (!in) { @@ -1014,6 +1037,45 @@ int gether_set_ifname(struct net_device *net, const char *name, int len) } EXPORT_SYMBOL_GPL(gether_set_ifname); +void gether_suspend(struct gether *link) +{ + struct eth_dev *dev = link->ioport; + unsigned long flags; + + if (!dev) + return; + + if (atomic_read(&dev->tx_qlen)) { + /* + * There is a transfer in progress. So we trigger a remote + * wakeup to inform the host. + */ + ether_wakeup_host(dev->port_usb); + return; + } + spin_lock_irqsave(&dev->lock, flags); + link->is_suspend = true; + spin_unlock_irqrestore(&dev->lock, flags); +} +EXPORT_SYMBOL_GPL(gether_suspend); + +void gether_resume(struct gether *link) +{ + struct eth_dev *dev = link->ioport; + unsigned long flags; + + if (!dev) + return; + + if (netif_queue_stopped(dev->net)) + netif_start_queue(dev->net); + + spin_lock_irqsave(&dev->lock, flags); + link->is_suspend = false; + spin_unlock_irqrestore(&dev->lock, flags); +} +EXPORT_SYMBOL_GPL(gether_resume); + /* * gether_cleanup - remove Ethernet-over-USB device * Context: may sleep @@ -1176,6 +1238,7 @@ void gether_disconnect(struct gether *link) spin_lock(&dev->lock); dev->port_usb = NULL; + link->is_suspend = false; spin_unlock(&dev->lock); } EXPORT_SYMBOL_GPL(gether_disconnect); diff --git a/drivers/usb/gadget/function/u_ether.h b/drivers/usb/gadget/function/u_ether.h index 4014454..851ee10 100644 --- a/drivers/usb/gadget/function/u_ether.h +++ b/drivers/usb/gadget/function/u_ether.h @@ -79,6 +79,7 @@ struct gether { /* called on network open/close */ void (*open)(struct gether *); void (*close)(struct gether *); + bool is_suspend; }; #define DEFAULT_FILTER (USB_CDC_PACKET_TYPE_BROADCAST \ @@ -258,6 +259,9 @@ int gether_set_ifname(struct net_device *net, const char *name, int len); void gether_cleanup(struct eth_dev *dev); +void gether_suspend(struct gether *link); +void gether_resume(struct gether *link); + /* connect/disconnect is handled by individual functions */ struct net_device *gether_connect(struct gether *); void gether_disconnect(struct gether *); -- 2.7.4