[Intel-wired-lan] [PATCH net v3] ice: Prevent set_channel from changing queues while RDMA active

[Dave Ertman]

The PF controls the set of queues that the RDMA auxiliary_driver requests
resources from.  The set_channel command will alter that pool and trigger a
reconfiguration of the VSI, which breaks RDMA functionality.

Prevent set_channel from executing when RDMA driver bound to auxiliary
device.

Fixes: 348048e724a0 ("ice: Implement iidc operations")
Signed-off-by: Dave Ertman <david.m.ertman at intel.com>
---
Changes since v2:
Added check for NULL pointer

Changes since v1:
Fixed typos and pointer reference
---
 drivers/net/ethernet/intel/ice/ice_ethtool.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c b/drivers/net/ethernet/intel/ice/ice_ethtool.c
index b7be84bbe72d..431ca2893197 100644
--- a/drivers/net/ethernet/intel/ice/ice_ethtool.c
+++ b/drivers/net/ethernet/intel/ice/ice_ethtool.c
@@ -3473,6 +3473,7 @@ static int ice_set_channels(struct net_device *dev, struct ethtool_channels *ch)
 	struct ice_pf *pf = vsi->back;
 	int new_rx = 0, new_tx = 0;
 	u32 curr_combined;
+	int ret = 0;
 
 	/* do not support changing channels in Safe Mode */
 	if (ice_is_safe_mode(pf)) {
@@ -3536,15 +3537,26 @@ static int ice_set_channels(struct net_device *dev, struct ethtool_channels *ch)
 		return -EINVAL;
 	}
 
+	mutex_lock(&pf->adev_mutex);
+	if (pf->adev && pf->adev->dev.driver) {
+		netdev_err(dev, "Cannot change channels when RDMA is active\n");
+		ret = -EINVAL;
+		goto adev_unlock;
+	}
+
 	ice_vsi_recfg_qs(vsi, new_rx, new_tx);
 
-	if (!netif_is_rxfh_configured(dev))
-		return ice_vsi_set_dflt_rss_lut(vsi, new_rx);
+	if (!netif_is_rxfh_configured(dev)) {
+		ret = ice_vsi_set_dflt_rss_lut(vsi, new_rx);
+		goto adev_unlock;
+	}
 
 	/* Update rss_size due to change in Rx queues */
 	vsi->rss_size = ice_get_valid_rss_size(&pf->hw, new_rx);
 
-	return 0;
+adev_unlock:
+	mutex_unlock(&pf->adev_mutex);
+	return ret;
 }
 
 /**
-- 
2.37.3