On Fri, Mar 24, 2023, Elson Roy Serrao wrote:
> 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 <quic_eserrao@xxxxxxxxxxx>
> ---
> 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
>
For the remote wakeup part of this patch:
Reviewed-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
Thanks,
Thinh
