| From 94a912be5014557b2a7e8ceeb231f1d709f6fdc0 Mon Sep 17 00:00:00 2001 |
| From: Johan Hovold <johan@kernel.org> |
| Date: Thu, 12 Jan 2017 14:56:21 +0100 |
| Subject: [PATCH] USB: serial: spcp8x5: fix modem-status handling |
| |
| commit 5ed8d41023751bdd3546f2fe4118304357efe8d2 upstream. |
| |
| 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. |
| |
| Fixes: e1ed212d8593 ("USB: spcp8x5: add proper modem-status support") |
| Cc: stable <stable@vger.kernel.org> |
| Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Johan Hovold <johan@kernel.org> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/usb/serial/spcp8x5.c b/drivers/usb/serial/spcp8x5.c |
| index 475e6c31b266..ddfd787c461c 100644 |
| --- a/drivers/usb/serial/spcp8x5.c |
| +++ b/drivers/usb/serial/spcp8x5.c |
| @@ -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; |
| -- |
| 2.12.0 |
| |
