From: Yanqing Wang ot_yanqing.wang@mediatek.com

Identify the cause of the suspend/resume hang: netif_carrier_off() is called during link state changes and becomes stuck while executing linkwatch_work().

To resolve this issue, call netif_device_detach() during the Ethernet suspend process to temporarily detach the network device from the kernel and prevent the suspend/resume hang.

Fixes: 8c7bd5a454ff ("net: ethernet: mtk-star-emac: new driver") Signed-off-by: Yanqing Wang ot_yanqing.wang@mediatek.com Signed-off-by: Macpaul Lin macpaul.lin@mediatek.com Signed-off-by: Biao Huang biao.huang@mediatek.com --- drivers/net/ethernet/mediatek/mtk_star_emac.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/mediatek/mtk_star_emac.c b/drivers/net/ethernet/mediatek/mtk_star_emac.c index b175119a6a7d..b83886a41121 100644 --- a/drivers/net/ethernet/mediatek/mtk_star_emac.c +++ b/drivers/net/ethernet/mediatek/mtk_star_emac.c @@ -1463,6 +1463,8 @@ static __maybe_unused int mtk_star_suspend(struct device *dev) if (netif_running(ndev)) mtk_star_disable(ndev);

+ netif_device_detach(ndev); + clk_bulk_disable_unprepare(MTK_STAR_NCLKS, priv->clks);

return 0; @@ -1487,6 +1489,8 @@ static __maybe_unused int mtk_star_resume(struct device *dev) clk_bulk_disable_unprepare(MTK_STAR_NCLKS, priv->clks); }

+ netif_device_attach(ndev); + return ret; }