[PATCH 3.2 34/95] ACM gadget: fix endianness in notifications

From: Ben Hutchings
Date: Sun Jul 16 2017 - 10:48:56 EST


3.2.91-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Oliver Neukum <oneukum@xxxxxxxx>

commit cdd7928df0d2efaa3270d711963773a08a4cc8ab upstream.

The gadget code exports the bitfield for serial status changes
over the wire in its internal endianness. The fix is to convert
to little endian before sending it over the wire.

Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx>
Tested-by: åç <momo1208@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
[bwh: Backported to 3.2: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/usb/gadget/f_acm.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/usb/gadget/f_acm.c
+++ b/drivers/usb/gadget/f_acm.c
@@ -497,13 +497,15 @@ static int acm_notify_serial_state(struc
{
struct usb_composite_dev *cdev = acm->port.func.config->cdev;
int status;
+ __le16 serial_state;

spin_lock(&acm->lock);
if (acm->notify_req) {
DBG(cdev, "acm ttyGS%d serial state %04x\n",
acm->port_num, acm->serial_state);
+ serial_state = cpu_to_le16(acm->serial_state);
status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
- 0, &acm->serial_state, sizeof(acm->serial_state));
+ 0, &serial_state, sizeof(acm->serial_state));
} else {
acm->pending = true;
status = 0;