Re: [PATCH v2 2/4] drivers: net: cpsw: fix wrong regs access in cpsw_remove

[Mugunthan V N]

On Thursday 28 July 2016 11:20 PM, Grygorii Strashko wrote:
> The L3 error will be generated and system will crash during unloading
> of CPSW driver if CPSW is used as module and ethX devices are down.
> This happens because CPSW can be power off by PM runtime now when ethX
> devices are down.
> 
> Hence, ensure that CPSW powered up by PM runtime before performing any
> deinitialization actions which require CPSW registers access. In case
> of PM runtime error just leave cpsw_remove() as we can't do anything
> anymore.
> 
> Signed-off-by: Grygorii Strashko 

Reviewed-by: Mugunthan V N 

Regards
Mugunthan V N

[PATCH v2 2/4] drivers: net: cpsw: fix wrong regs access in cpsw_remove

[Grygorii Strashko]

The L3 error will be generated and system will crash during unloading
of CPSW driver if CPSW is used as module and ethX devices are down.
This happens because CPSW can be power off by PM runtime now when ethX
devices are down.

Hence, ensure that CPSW powered up by PM runtime before performing any
deinitialization actions which require CPSW registers access. In case
of PM runtime error just leave cpsw_remove() as we can't do anything
anymore.

Signed-off-by: Grygorii Strashko 
---
 drivers/net/ethernet/ti/cpsw.c | 10 +-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 8f1eab9..ec6f473 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -2579,6 +2579,13 @@ static int cpsw_remove(struct platform_device *pdev)
 {
struct net_device *ndev = platform_get_drvdata(pdev);
struct cpsw_priv *priv = netdev_priv(ndev);
+   int ret;
+
+   ret = pm_runtime_get_sync(>dev);
+   if (ret < 0) {
+   pm_runtime_put_noidle(>dev);
+   return ret;
+   }
 
if (priv->data.dual_emac)
unregister_netdev(cpsw_get_slave_ndev(priv, 1));
@@ -2586,8 +2593,9 @@ static int cpsw_remove(struct platform_device *pdev)
 
cpsw_ale_destroy(priv->ale);
cpdma_ctlr_destroy(priv->dma);
-   pm_runtime_disable(>dev);
device_for_each_child(>dev, NULL, cpsw_remove_child_device);
+   pm_runtime_put_sync(>dev);
+   pm_runtime_disable(>dev);
if (priv->data.dual_emac)
free_netdev(cpsw_get_slave_ndev(priv, 1));
free_netdev(ndev);
-- 
2.9.2