patch "USB: serial: spcp8x5: fix modem-status handling" added to usb-next

This is a note to let you know that I've just added the patch titled

USB: serial: spcp8x5: fix modem-status handling

to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-next branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will also be merged in the next major kernel release during the merge window.

If you have any questions about this process, please let me know.

From: Johan Hovold <[email protected]>
Date: Thu, 12 Jan 2017 14:56:21 +0100
Subject: USB: serial: spcp8x5: fix modem-status handling

Make sure to detect short control transfers and return zero on success when retrieving the modem status.

This fixes the TIOCMGET implementation which since e1ed212d8593 ("USB:
spcp8x5: add proper modem-status support") has returned TIOCM_LE on successful retrieval, and avoids leaking bits from the stack on short transfers.

This also fixes the carrier-detect implementation which since the above mentioned commit unconditionally has returned true.

---
 drivers/usb/serial/spcp8x5.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

index 475e6c31b266..ddfd787c461c 100644
@@ -232,11 +232,17 @@ static int spcp8x5_get_msr(struct usb_serial_port *port, u8 *status)
 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 			      GET_UART_STATUS, GET_UART_STATUS_TYPE,
 			      0, GET_UART_STATUS_MSR, buf, 1, 100);
-	if (ret < 0)
+	if (ret < 1) {
 		dev_err(&port->dev, "failed to get modem status: %d\n", ret);
+		if (ret >= 0)
+			ret = -EIO;
+		goto out;
+	}
 
 	dev_dbg(&port->dev, "0xc0:0x22:0:6  %d - 0x02%x\n", ret, *buf);
 	*status = *buf;
+	ret = 0;
+out:
 	kfree(buf);
 
 	return ret;

2.11.1