netdev - [PATCH net 5/5] can: m_can: m_can_close(): stop clocks after device has been shut down

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240912075804.2825408-6-mkl@pengutronix.de>
Date: Thu, 12 Sep 2024 09:50:54 +0200
From: Marc Kleine-Budde <mkl@...gutronix.de>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net,
	kuba@...nel.org,
	linux-can@...r.kernel.org,
	kernel@...gutronix.de,
	Marc Kleine-Budde <mkl@...gutronix.de>
Subject: [PATCH net 5/5] can: m_can: m_can_close(): stop clocks after device has been shut down

After calling m_can_stop() an interrupt may be pending or NAPI might
still be executed. This means the driver might still touch registers
of the IP core after the clocks have been disabled. This is not good
practice and might lead to aborts depending on the SoC integration.

To avoid these potential problems, make m_can_close() symmetric to
m_can_open(), i.e. stop the clocks at the end, right before shutting
down the transceiver.

Fixes: e0d1f4816f2a ("can: m_can: add Bosch M_CAN controller support")
Link: https://patch.msgid.link/20240910-can-m_can-fix-ifup-v3-2-6c1720ba45ce@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@...gutronix.de>
---
 drivers/net/can/m_can/m_can.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index c1a07013433e..7fec04b024d5 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -1764,7 +1764,6 @@ static int m_can_close(struct net_device *dev)
 	netif_stop_queue(dev);
 
 	m_can_stop(dev);
-	m_can_clk_stop(cdev);
 	free_irq(dev->irq, dev);
 
 	m_can_clean(dev);
@@ -1779,6 +1778,7 @@ static int m_can_close(struct net_device *dev)
 
 	close_candev(dev);
 
+	m_can_clk_stop(cdev);
 	phy_power_off(cdev->transceiver);
 
 	return 0;
-- 
2.45.2