usb: serial: silence all non-critical read errors

commit aa8e22128b40590b291cd13512098bf258a7e6c5 upstream.

If a USB serial device is unplugged while there is an active program
using the device it may spam the logs with -EPROTO (71) messages as it
attempts to retry.

Most serial usb drivers (metro-usb, pl2303, mos7840, ...) only output
these messages for debugging.  The generic driver treats these as
errors.

Change the default output for the generic serial driver from error to
debug to silence these non-critical errors.

Signed-off-by: Jeremiah Mahler <jmmahler@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index 904ab353ecf29f929003c97f74c190a9ca45beaf..c44b911937e8d7440f98770074d670a6ae812edd 100644 (file)
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -374,7 +374,7 @@ void usb_serial_generic_read_bulk_callback(struct urb *urb)
                                                        __func__, urb->status);
                return;
        default:
-               dev_err(&port->dev, "%s - nonzero urb status: %d\n",
+               dev_dbg(&port->dev, "%s - nonzero urb status: %d\n",
                                                        __func__, urb->status);
                goto resubmit;
        }