[PATCH 5.4 13/34] USB: serial: usb_wwan: do not resubmit rx urb on fatal errors

Greg Kroah-Hartman
2020-06-09T18:04:36Z

From: Bin Liu <b-liu@ti.com>

commit 986c1748c84d7727defeaeca74a73b37f7d5cce1 upstream.

usb_wwan_indat_callback() shouldn't resubmit rx urb if the previous urb
status is a fatal error. Or the usb controller would keep processing the
new urbs then run into interrupt storm, and has no chance to recover.

Fixes: 6c1ee66a0b2b ("USB-Serial: Fix error handling of usb_wwan")
Cc: stable@vger.kernel.org
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/serial/usb_wwan.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/usb/serial/usb_wwan.c
+++ b/drivers/usb/serial/usb_wwan.c
@@ -270,6 +270,10 @@ static void usb_wwan_indat_callback(stru
if (status) {
dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n",
__func__, status, endpoint);
+
+ /* don't resubmit on fatal errors */
+ if (status == -ESHUTDOWN || status == -ENOENT)
+ return;
} else {
if (urb->actual_length) {
tty_insert_flip_string(&port->port, data,