From 198179daff54cc2f059daf3829b916b06e26442f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
Date: Wed, 10 May 2023 22:00:20 +0200
Subject: [PATCH 2/2] net: fec: Better handle pm_runtime_get() failing in
.remove()
Patch-mainline: v6.4-rc3
Git-commit: f816b9829b19394d318e01953aa3b2721bca040d
References: git-fixes
In the (unlikely) event that pm_runtime_get() (disguised as
pm_runtime_resume_and_get()) fails, the remove callback returned an
error early. The problem with this is that the driver core ignores the
error value and continues removing the device. This results in a
resource leak. Worse the devm allocated resources are freed and so if a
callback of the driver is called later the register mapping is already
gone which probably results in a crash.
Fixes: a31eda65ba21 ("net: fec: fix clock count mis-match")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20230510200020.1534610-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
drivers/net/ethernet/freescale/fec_main.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 8f48ad0f7513..b9af8051a479 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -3610,7 +3610,9 @@ fec_drv_remove(struct platform_device *pdev)
ret = pm_runtime_get_sync(&pdev->dev);
if (ret < 0)
- return ret;
+ dev_err(&pdev->dev,
+ "Failed to resume device in remove callback (%pe)\n",
+ ERR_PTR(ret));
cancel_work_sync(&fep->tx_timeout_work);
fec_ptp_stop(pdev);
@@ -3623,8 +3625,13 @@ fec_drv_remove(struct platform_device *pdev)
of_phy_deregister_fixed_link(np);
of_node_put(fep->phy_node);
- clk_disable_unprepare(fep->clk_ahb);
- clk_disable_unprepare(fep->clk_ipg);
+ /* After pm_runtime_get_sync() failed, the clks are still off, so skip
+ * disabling them again.
+ */
+ if (ret >= 0) {
+ clk_disable_unprepare(fep->clk_ahb);
+ clk_disable_unprepare(fep->clk_ipg);
+ }
pm_runtime_put_noidle(&pdev->dev);
pm_runtime_disable(&pdev->dev);
--
2.16.4