From 587585e1bbebc250d46ebb0eeaf986d9c3c01c69 Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Wed, 7 Dec 2022 15:04:55 +0100 Subject: [PATCH] net: ethernet: mtk_wed: fix possible deadlock if mtk_wed_wo_init fails Introduce __mtk_wed_detach() in order to avoid a deadlock in mtk_wed_attach routine if mtk_wed_wo_init fails since both mtk_wed_attach and mtk_wed_detach run holding hw_lock mutex. Fixes: 4c5de09eb0d0 ("net: ethernet: mtk_wed: add configure wed wo support") Signed-off-by: Lorenzo Bianconi Reviewed-by: Leon Romanovsky Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/mediatek/mtk_wed.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/mediatek/mtk_wed.c b/drivers/net/ethernet/mediatek/mtk_wed.c index 4ef23eadd69ee..a6271449617fc 100644 --- a/drivers/net/ethernet/mediatek/mtk_wed.c +++ b/drivers/net/ethernet/mediatek/mtk_wed.c @@ -577,12 +577,10 @@ mtk_wed_deinit(struct mtk_wed_device *dev) } static void -mtk_wed_detach(struct mtk_wed_device *dev) +__mtk_wed_detach(struct mtk_wed_device *dev) { struct mtk_wed_hw *hw = dev->hw; - mutex_lock(&hw_lock); - mtk_wed_deinit(dev); mtk_wdma_rx_reset(dev); @@ -615,6 +613,13 @@ mtk_wed_detach(struct mtk_wed_device *dev) module_put(THIS_MODULE); hw->wed_dev = NULL; +} + +static void +mtk_wed_detach(struct mtk_wed_device *dev) +{ + mutex_lock(&hw_lock); + __mtk_wed_detach(dev); mutex_unlock(&hw_lock); } @@ -1497,8 +1502,10 @@ mtk_wed_attach(struct mtk_wed_device *dev) ret = mtk_wed_wo_init(hw); } out: - if (ret) - mtk_wed_detach(dev); + if (ret) { + dev_err(dev->hw->dev, "failed to attach wed device\n"); + __mtk_wed_detach(dev); + } unlock: mutex_unlock(&hw_lock); -- 2.30.2