From: Sondhauß, Jan Jan.Sondhauss@wago.com
[ Upstream commit 2844e2434385819f674d1fb4130c308c50ba681e ]
cpsw_ethtool_begin directly returns the result of pm_runtime_get_sync when successful. pm_runtime_get_sync returns -error code on failure and 0 on successful resume but also 1 when the device is already active. So the common case for cpsw_ethtool_begin is to return 1. That leads to inconsistent calls to pm_runtime_put in the call-chain so that pm_runtime_put is called one too many times and as result leaving the cpsw dev behind suspended.
The suspended cpsw dev leads to an access violation later on by different parts of the cpsw driver.
Fix this by calling the return-friendly pm_runtime_resume_and_get function.
Fixes: d43c65b05b84 ("ethtool: runtime-resume netdev parent in ethnl_ops_begin") Signed-off-by: Jan Sondhauss jan.sondhauss@wago.com Reviewed-by: Vignesh Raghavendra vigneshr@ti.com Link: https://lore.kernel.org/r/20220323084725.65864-1-jan.sondhauss@wago.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/ti/cpsw_ethtool.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/ti/cpsw_ethtool.c b/drivers/net/ethernet/ti/cpsw_ethtool.c index 158c8d3793f4..b5bae6324970 100644 --- a/drivers/net/ethernet/ti/cpsw_ethtool.c +++ b/drivers/net/ethernet/ti/cpsw_ethtool.c @@ -364,11 +364,9 @@ int cpsw_ethtool_op_begin(struct net_device *ndev) struct cpsw_common *cpsw = priv->cpsw; int ret;
- ret = pm_runtime_get_sync(cpsw->dev); - if (ret < 0) { + ret = pm_runtime_resume_and_get(cpsw->dev); + if (ret < 0) cpsw_err(priv, drv, "ethtool begin failed %d\n", ret); - pm_runtime_put_noidle(cpsw->dev); - }
return ret; }