net: ravb: Do not apply features to hardware if the interface is down

Do not apply features to hardware if the interface is down. In case runtime
PM is enabled, and while the interface is down, the IP will be in reset
mode (as for some platforms disabling the clocks will switch the IP to
reset mode, which will lead to losing register contents) and applying
settings in reset mode is not an option. Instead, cache the features and
apply them in ravb_open() through ravb_emac_init().

To avoid accessing the hardware while the interface is down
pm_runtime_active() check was introduced. Along with it the device runtime
PM usage counter has been incremented to avoid disabling the device clocks
while the check is in progress (if any).

Commit prepares for the addition of runtime PM.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 1322eee524ccc107516ceb55a9b2ed2f5a849548..a74348eb7ba12c021aa53b9c1b84d8fd8c3fae07 100644 (file)
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2560,9 +2560,18 @@ static int ravb_set_features(struct net_device *ndev,
 {
        struct ravb_private *priv = netdev_priv(ndev);
        const struct ravb_hw_info *info = priv->info;
+       struct device *dev = &priv->pdev->dev;
        int ret;
 
-       ret = info->set_feature(ndev, features);
+       pm_runtime_get_noresume(dev);
+
+       if (pm_runtime_active(dev))
+               ret = info->set_feature(ndev, features);
+       else
+               ret = 0;
+
+       pm_runtime_put_noidle(dev);
+
        if (ret)
                return ret;