From 2abb5792387eb188b12051337d5dcd2cba615cb0 Mon Sep 17 00:00:00 2001 From: Subash Abhinov Kasiviswanathan Date: Wed, 1 Apr 2020 15:23:55 -0600 Subject: [PATCH] net: qualcomm: rmnet: Allow configuration updates to existing devices This allows the changelink operation to succeed if the mux_id was specified as an argument. Note that the mux_id must match the existing mux_id of the rmnet device or should be an unused mux_id. Fixes: 1dc49e9d164c ("net: rmnet: do not allow to change mux id if mux id is duplicated") Reported-and-tested-by: Alex Elder Signed-off-by: Sean Tranchetti Signed-off-by: Subash Abhinov Kasiviswanathan Signed-off-by: David S. Miller --- .../ethernet/qualcomm/rmnet/rmnet_config.c | 33 +++++++++++-------- 1 file changed, 20 insertions(+), 13 deletions(-) diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c index 1305522f72d6..40efe60eff8d 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c @@ -282,7 +282,6 @@ static int rmnet_changelink(struct net_device *dev, struct nlattr *tb[], { struct rmnet_priv *priv = netdev_priv(dev); struct net_device *real_dev; - struct rmnet_endpoint *ep; struct rmnet_port *port; u16 mux_id; @@ -297,19 +296,27 @@ static int rmnet_changelink(struct net_device *dev, struct nlattr *tb[], if (data[IFLA_RMNET_MUX_ID]) { mux_id = nla_get_u16(data[IFLA_RMNET_MUX_ID]); - if (rmnet_get_endpoint(port, mux_id)) { - NL_SET_ERR_MSG_MOD(extack, "MUX ID already exists"); - return -EINVAL; + + if (mux_id != priv->mux_id) { + struct rmnet_endpoint *ep; + + ep = rmnet_get_endpoint(port, priv->mux_id); + if (!ep) + return -ENODEV; + + if (rmnet_get_endpoint(port, mux_id)) { + NL_SET_ERR_MSG_MOD(extack, + "MUX ID already exists"); + return -EINVAL; + } + + hlist_del_init_rcu(&ep->hlnode); + hlist_add_head_rcu(&ep->hlnode, + &port->muxed_ep[mux_id]); + + ep->mux_id = mux_id; + priv->mux_id = mux_id; } - ep = rmnet_get_endpoint(port, priv->mux_id); - if (!ep) - return -ENODEV; - - hlist_del_init_rcu(&ep->hlnode); - hlist_add_head_rcu(&ep->hlnode, &port->muxed_ep[mux_id]); - - ep->mux_id = mux_id; - priv->mux_id = mux_id; } if (data[IFLA_RMNET_FLAGS]) {