[PATCH 3.18 024/120] USB: serial: kobil_sct: fix modem-status error handling

Greg Kroah-Hartman
2018-10-11T15:38:27Z

From: Johan Hovold <johan@kernel.org>

[ Upstream commit a420b5d939ee58f1d950f0ea782834056520aeaa ]

Make sure to return -EIO in case of a short modem-status read request.

While at it, split the debug message to not include the (zeroed)
transfer-buffer content in case of errors.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/serial/kobil_sct.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

--- a/drivers/usb/serial/kobil_sct.c
+++ b/drivers/usb/serial/kobil_sct.c
@@ -396,12 +396,20 @@ static int kobil_tiocmget(struct tty_str
transfer_buffer_length,
KOBIL_TIMEOUT);

- dev_dbg(&port->dev, "%s - Send get_status_line_state URB returns: %i. Statusline: %02x\n",
- __func__, result, transfer_buffer[0]);
+ dev_dbg(&port->dev, "Send get_status_line_state URB returns: %i\n",
+ result);
+ if (result < 1) {
+ if (result >= 0)
+ result = -EIO;
+ goto out_free;
+ }
+
+ dev_dbg(&port->dev, "Statusline: %02x\n", transfer_buffer[0]);

result = 0;
if ((transfer_buffer[0] & SUSBCR_GSL_DSR) != 0)
result = TIOCM_DSR;
+out_free:
kfree(transfer_buffer);
return result;
}