Commit 03c42714 authored by Frieder Schrempf's avatar Frieder Schrempf Committed by Marc Kleine-Budde
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can: mcp251x: fix resume from sleep before interface was brought up 

Since 8ce8c0ab the driver queues work via priv->restart_work when
resuming after suspend, even when the interface was not previously
enabled. This causes a null dereference error as the workqueue is only
allocated and initialized in mcp251x_open().

To fix this we move the workqueue init to mcp251x_can_probe() as there
is no reason to do it later and repeat it whenever mcp251x_open() is
called.

Fixes: 8ce8c0ab ("can: mcp251x: only reset hardware as required")
Link: https://lore.kernel.org/r/17d5d714-b468-482f-f37a-482e3d6df84e@kontron.de


Signed-off-by: default avatarFrieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
[mkl: fix error handling in mcp251x_stop()]
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 4376ea42

drivers/net/can/spi/mcp251x.c

+18 −17
Original line number Diff line number Diff line
@@ -956,8 +956,6 @@ static int mcp251x_stop(struct net_device *net) 


	priv->force_quit = 1;

	free_irq(spi->irq, priv);

	destroy_workqueue(priv->wq);

	priv->wq = NULL;



	mutex_lock(&priv->mcp_lock);
@@ -1224,24 +1222,15 @@ static int mcp251x_open(struct net_device *net) 
		goto out_close;

	}



	priv->wq = alloc_workqueue("mcp251x_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,

				   0);

	if (!priv->wq) {

		ret = -ENOMEM;

		goto out_clean;

	}

	INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler);

	INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler);



	ret = mcp251x_hw_wake(spi);

	if (ret)

		goto out_free_wq;

		goto out_free_irq;

	ret = mcp251x_setup(net, spi);

	if (ret)

		goto out_free_wq;

		goto out_free_irq;

	ret = mcp251x_set_normal_mode(spi);

	if (ret)

		goto out_free_wq;

		goto out_free_irq;



	can_led_event(net, CAN_LED_EVENT_OPEN);
@@ -1250,9 +1239,7 @@ static int mcp251x_open(struct net_device *net) 


	return 0;



out_free_wq:

	destroy_workqueue(priv->wq);

out_clean:

out_free_irq:

	free_irq(spi->irq, priv);

	mcp251x_hw_sleep(spi);

out_close:
@@ -1373,6 +1360,15 @@ static int mcp251x_can_probe(struct spi_device *spi) 
	if (ret)

		goto out_clk;



	priv->wq = alloc_workqueue("mcp251x_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,

				   0);

	if (!priv->wq) {

		ret = -ENOMEM;

		goto out_clk;

	}

	INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler);

	INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler);



	priv->spi = spi;

	mutex_init(&priv->mcp_lock);
@@ -1417,6 +1413,8 @@ static int mcp251x_can_probe(struct spi_device *spi) 
	return 0;



error_probe:

	destroy_workqueue(priv->wq);

	priv->wq = NULL;

	mcp251x_power_enable(priv->power, 0);



out_clk:
@@ -1438,6 +1436,9 @@ static int mcp251x_can_remove(struct spi_device *spi) 


	mcp251x_power_enable(priv->power, 0);



	destroy_workqueue(priv->wq);

	priv->wq = NULL;



	clk_disable_unprepare(priv->clk);



	free_candev(net);