From: Oliver Neukum <oneukum@xxxxxxxx> commit e4c77070ad45fc940af1d7fb1e637c349e848951 upstream. This failure is so common that logging an error here amounts to spamming log files. Reviewed-by: Bruno Thomsen <bruno.thomsen@xxxxxxxxx> Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210311130126.15972-2-oneukum@xxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/class/cdc-acm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -659,7 +659,8 @@ static void acm_port_dtr_rts(struct tty_ res = acm_set_control(acm, val); if (res && (acm->ctrl_caps & USB_CDC_CAP_LINE)) - dev_err(&acm->control->dev, "failed to set dtr/rts\n"); + /* This is broken in too many devices to spam the logs */ + dev_dbg(&acm->control->dev, "failed to set dtr/rts\n"); } static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)