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

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-testing 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 be merged to the usb-next branch sometime soon, after it passes testing, and the merge window is open.

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