From 2e32a401ea5df22ab899f4da3e5e1b448b2df51a Mon Sep 17 00:00:00 2001 From: Alexey Min Date: Thu, 7 Mar 2019 17:25:48 +0300 Subject: [PATCH 5/6] usb_gadget: set random rndis host MAC address to prevent zero address This fixes zero host MAC: rndis0: MAC f6:45:91:9b:4e:43 rndis0: HOST MAC 00:00:00:00:00:00 and allows devive to automatically obtain IP addrest on PC host side zero MAC address prevented interface from autoconfiguring --- drivers/usb/gadget/function/u_ether.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/u_ether.c b/drivers/usb/gadget/u_ether.c index bf8b64d904c..9ce3ab6de34 100644 --- a/drivers/usb/gadget/u_ether.c +++ b/drivers/usb/gadget/u_ether.c @@ -1224,8 +1224,16 @@ dev_warn(&g->dev, "using random %s ethernet address\n", "self"); #ifdef CONFIG_USB_ANDROID_SAMSUNG_COMPOSITE - memcpy(dev->host_mac, ethaddr, ETH_ALEN); - printk(KERN_DEBUG "usb: set unique host mac\n"); + if ((ethaddr[0] == 0x00) && (ethaddr[1] == 0x00) && + (ethaddr[2] == 0x00) && (ethaddr[3] == 0x00) && + (ethaddr[4] == 0x00) && (ethaddr[5] == 0x00)) { + printk(KERN_DEBUG "%s: no unique host MAC was set, generate random\n", __func__); + /* we can use random_ether_addr() from include/linux/etherdevice.h */ + random_ether_addr(ethaddr); + } else { + printk(KERN_DEBUG "%s: set unique host mac\n", __func__); + } + memcpy(dev->host_mac, ethaddr, ETH_ALEN); #else if (get_ether_addr(host_addr, dev->host_mac)) dev_warn(&g->dev,