USB-CDC: Prevent rx_req being enqueued twice
After gadget reinitializaton (after tftp has been done once)
packet_received may become equal to 1 due to nuking OUT_EP
while disabling it in eth_reset_config.
rx_submit called from usb_eth_init queues rx_req first time.
But the first call of usb_eth_recv from NetLoop queues rx_req
again due to packet_received = 1.
The following flow shows the path of functions calls when
this happens:
net/net.c:NetLoop
|
+-net/eth.c:eth_init
| ether.c:usb_eth_init
| |
| +-udc_driver:usb_gadget_handle_interrupts
| | udc_driver:...
| | ether.c:eth_setup
| | ether.c:eth_set_config
| | ether.c:eth_reset_config
| | udc_driver:usb_ep_disable
| | udc_driver:nuke
| | ether.c:rx_complete
| | ether.c: packet_received = 1;
| |
| +-ether.c:rx_submit
| udc_driver:usb_ep_queue --- The first time when rx_req is queued
|
+-net/eth.c:eth_rx
ether.c:usb_eth_recv
|
+-udc_driver:usb_gadget_handle_interrupts
| udc_driver:... --- no interrupts, returning
+-ether.c: if (packet_received) { ...
ether.c:rx_submit
udc_driver:usb_ep_queue --- The second time!
Signed-off-by: Vitaly Kuzmichev <vkuzmichev@mvista.com>
diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c
index 8f5eec1..b22ca90 100644
--- a/drivers/usb/gadget/ether.c
+++ b/drivers/usb/gadget/ether.c
@@ -1810,6 +1810,7 @@
usb_gadget_handle_interrupts();
}
+ packet_received = 0;
rx_submit(dev, dev->rx_req, 0);
return 0;
fail: