From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vikas Bansal Subject: [PATCH] Adding Reset resume support for CDC-EEM driver. Date: Mon, 21 Dec 2015 17:38:51 +0530 Message-ID: <1450699731-4666-1-git-send-email-vikas.bansal@samsung.com> Cc: sumit.batra@samsung.com, Vikas Bansal To: oneukum@suse.de, netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Pre-Condition At the time of reset resume of a USB device, both self and bus powered devices might go to a low power state or power off state depending on the acceptable suspend time power of the system. In case the device experiences a power glitch or completely powers off during suspend-resume, the device will lose its internal state and hence it'll again need a set interface from class driver on reset resume operation. Issue So far our experiments were based on a USB gadget working on cdc_eem protocol. We have seen that device is unable to continue the packet transfer on bulk endpoints after the reset resume operation. Solution We have added a .reset_resume function for cdc_eem protocol which sends a set interface command on the Control endpoint. And calls the existing usbnet_resume thereafter Signed-off-by: Vikas Bansal Signed-off-by: Sumit Batra diff --git a/drivers/net/usb/cdc_eem.c b/drivers/net/usb/cdc_eem.c index f7180f8..1f6f7ea 100644 --- a/drivers/net/usb/cdc_eem.c +++ b/drivers/net/usb/cdc_eem.c @@ -342,6 +342,19 @@ next: return 1; } +static int cdc_eem_resume(struct usb_interface *intf) +{ + int ret = 0; + struct usbnet *dev = usb_get_intfdata(intf); + + ret = usbnet_get_endpoints(dev, intf); + if(ret < 0) + goto err; + ret = usbnet_resume(intf); +err: + return ret; +} + static const struct driver_info eem_info = { .description = "CDC EEM Device", .flags = FLAG_ETHER | FLAG_POINTTOPOINT, @@ -371,6 +384,7 @@ static struct usb_driver eem_driver = { .disconnect = usbnet_disconnect, .suspend = usbnet_suspend, .resume = usbnet_resume, + .reset_resume = cdc_eem_resume, .disable_hub_initiated_lpm = 1, };