[PATCH 04/15] drivers: net: cpsw: ethtool: fix accessing to suspended device

[Grygorii Strashko]

The CPSW might be suspended by RPM if all ethX interfaces are down,
but it still could be accesible through ethtool interfce. In this case
ethtool operations, requiring registers access, will cause L3 errors and
CPSW crash.

Hence, fix it by adding RPM get/put calls in ethtool callbcaks which
can access CPSW registers: .set_coalesce(), .get_ethtool_stats(),
.set_pauseparam(), .get_regs()

Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
---
 drivers/net/ethernet/ti/cpsw.c | 36 +++++++++++++++++++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index ba81d4e..1ba0c09 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -931,6 +931,13 @@ static int cpsw_set_coalesce(struct net_device *ndev,
 	u32 prescale = 0;
 	u32 addnl_dvdr = 1;
 	u32 coal_intvl = 0;
+	int ret;
+
+	ret = pm_runtime_get_sync(&priv->pdev->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(&priv->pdev->dev);
+		return ret;
+	}
 
 	coal_intvl = coal->rx_coalesce_usecs;
 
@@ -985,6 +992,8 @@ update_return:
 		priv->coal_intvl = coal_intvl;
 	}
 
+	pm_runtime_put(&priv->pdev->dev);
+
 	return 0;
 }
 
@@ -1022,7 +1031,13 @@ static void cpsw_get_ethtool_stats(struct net_device *ndev,
 	struct cpdma_chan_stats tx_stats;
 	u32 val;
 	u8 *p;
-	int i;
+	int i, ret;
+
+	ret = pm_runtime_get_sync(&priv->pdev->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(&priv->pdev->dev);
+		return;
+	}
 
 	/* Collect Davinci CPDMA stats for Rx and Tx Channel */
 	cpdma_chan_get_stats(priv->rxch, &rx_stats);
@@ -1049,6 +1064,8 @@ static void cpsw_get_ethtool_stats(struct net_device *ndev,
 			break;
 		}
 	}
+
+	pm_runtime_put(&priv->pdev->dev);
 }
 
 static int cpsw_common_res_usage_state(struct cpsw_priv *priv)
@@ -1780,11 +1797,20 @@ static void cpsw_get_regs(struct net_device *ndev,
 {
 	struct cpsw_priv *priv = netdev_priv(ndev);
 	u32 *reg = p;
+	int ret;
+
+	ret = pm_runtime_get_sync(&priv->pdev->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(&priv->pdev->dev);
+		return;
+	}
 
 	/* update CPSW IP version */
 	regs->version = priv->version;
 
 	cpsw_ale_dump(priv->ale, reg);
+
+	pm_runtime_put(&priv->pdev->dev);
 }
 
 static void cpsw_get_drvinfo(struct net_device *ndev,
@@ -1902,12 +1928,20 @@ static int cpsw_set_pauseparam(struct net_device *ndev,
 {
 	struct cpsw_priv *priv = netdev_priv(ndev);
 	bool link;
+	int ret;
+
+	ret = pm_runtime_get_sync(&priv->pdev->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(&priv->pdev->dev);
+		return ret;
+	}
 
 	priv->rx_pause = pause->rx_pause ? true : false;
 	priv->tx_pause = pause->tx_pause ? true : false;
 
 	for_each_slave(priv, _cpsw_adjust_link, priv, &link);
 
+	pm_runtime_put(&priv->pdev->dev);
 	return 0;
 }
 
-- 
2.8.4