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: 4c5de09 ("net: ethernet: mtk_wed: add configure wed wo support") Signed-off-by: Lorenzo Bianconi <[email protected]> Reviewed-by: Leon Romanovsky <[email protected]> Signed-off-by: Jakub Kicinski <[email protected]>
majek · Dec 9, 2022 · 587585e · 587585e
1 parent c79e0af
commit 587585e
Showing 1 changed file with 12 additions and 5 deletions.
diff --git 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);