net: usb: Handle Zero length packet
RMNET control driver does not handle zero length packet and
passes it on as QMI command response received from mdm device
to userspace. mdm device is erroneously sending zero length
packet to the RMNET control driver which userspace treats as
an error. Hence add a check for zero length packet and do not
pass it on to userspace.
Change-Id: Id18e2f6ffca1692243a3d89a25bb3ccafd7d5b89
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>
diff --git a/drivers/net/usb/rmnet_usb_ctrl.c b/drivers/net/usb/rmnet_usb_ctrl.c
index ebd58ab..29968a6 100644
--- a/drivers/net/usb/rmnet_usb_ctrl.c
+++ b/drivers/net/usb/rmnet_usb_ctrl.c
@@ -231,6 +231,12 @@
cpkt = urb->transfer_buffer;
cpkt_size = urb->actual_length;
+ if (!cpkt_size) {
+ dev->zlp_cnt++;
+ dev_dbg(dev->devicep, "%s: zero length pkt received\n",
+ __func__);
+ goto resubmit_int_urb;
+ }
list_elem = kmalloc(sizeof(struct ctrl_pkt_list_elem), GFP_ATOMIC);
if (!list_elem) {
@@ -856,6 +862,7 @@
"cbits_tolocal: %d\n"
"cbits_tomdm: %d\n"
"mdm_wait_timeout: %u\n"
+ "zlp_cnt: %u\n"
"dev opened: %s\n",
dev, dev->name,
dev->snd_encap_cmd_cnt,
@@ -866,6 +873,7 @@
dev->cbits_tolocal,
dev->cbits_tomdm,
dev->mdm_wait_timeout,
+ dev->zlp_cnt,
dev->is_opened ? "OPEN" : "CLOSE");
}
@@ -893,6 +901,7 @@
dev->get_encap_resp_cnt = 0;
dev->set_ctrl_line_state_cnt = 0;
dev->tx_ctrl_err_cnt = 0;
+ dev->zlp_cnt = 0;
}
return count;
}
diff --git a/drivers/net/usb/rmnet_usb_ctrl.h b/drivers/net/usb/rmnet_usb_ctrl.h
index f6e5876..bc07726 100644
--- a/drivers/net/usb/rmnet_usb_ctrl.h
+++ b/drivers/net/usb/rmnet_usb_ctrl.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2011, Code Aurora Forum. All rights reserved.
+/* Copyright (c) 2011-2012, Code Aurora Forum. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
@@ -66,6 +66,7 @@
unsigned int resp_avail_cnt;
unsigned int set_ctrl_line_state_cnt;
unsigned int tx_ctrl_err_cnt;
+ unsigned int zlp_cnt;
};
extern struct rmnet_ctrl_dev *ctrl_dev[];