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From:   gregkh@linuxfoundation.org
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Aleksander Morgado <aleksander@aleksander.es>,
        Daniele Palmas <dnlplm@gmail.com>,
        =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@mork.no>,
        "David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.19 023/120] net: usb: qmi_wwan: allow qmimux add/del with master up
Date:   Mon, 15 Mar 2021 14:56:14 +0100
Message-Id: <20210315135720.755618615@linuxfoundation.org>
In-Reply-To: <20210315135720.002213995@linuxfoundation.org>
References: <20210315135720.002213995@linuxfoundation.org>
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

From: Daniele Palmas <dnlplm@gmail.com>

commit 6c59cff38e66584ae3ac6c2f0cbd8d039c710ba7 upstream.

There's no reason for preventing the creation and removal
of qmimux network interfaces when the underlying interface
is up.

This makes qmi_wwan mux implementation more similar to the
rmnet one, simplifying userspace management of the same
logical interfaces.

Fixes: c6adf77953bc ("net: usb: qmi_wwan: add qmap mux protocol support")
Reported-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/usb/qmi_wwan.c |   14 --------------
 1 file changed, 14 deletions(-)

--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -378,13 +378,6 @@ static ssize_t add_mux_store(struct devi
 		goto err;
 	}
 
-	/* we don't want to modify a running netdev */
-	if (netif_running(dev->net)) {
-		netdev_err(dev->net, "Cannot change a running device\n");
-		ret = -EBUSY;
-		goto err;
-	}
-
 	ret = qmimux_register_device(dev->net, mux_id);
 	if (!ret) {
 		info->flags |= QMI_WWAN_FLAG_MUX;
@@ -414,13 +407,6 @@ static ssize_t del_mux_store(struct devi
 	if (!rtnl_trylock())
 		return restart_syscall();
 
-	/* we don't want to modify a running netdev */
-	if (netif_running(dev->net)) {
-		netdev_err(dev->net, "Cannot change a running device\n");
-		ret = -EBUSY;
-		goto err;
-	}
-
 	del_dev = qmimux_find_dev(dev, mux_id);
 	if (!del_dev) {
 		netdev_err(dev->net, "mux_id not present\n");