From: Frieder Schrempf frieder.schrempf@kontron.de

Since 8ce8c0abcba3 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: 8ce8c0abcba3 ("can: mcp251x: only reset hardware as required") Cc: stable@vger.kernel.org Signed-off-by: Frieder Schrempf frieder.schrempf@kontron.de Reviewed-by: Andy Shevchenko andriy.shevchenko@linux.intel.com --- Changes in v2: * Remove the out_clean label in mcp251x_open() * Add Andy's R-b tag * Add 'From' tag

Hi Marc, I'm sending a v2 mainly because I noticed that v1 is missing the 'From' tag and as my company's mailserver always sends my name reversed this causes incorrect author information in git. So if possible you could fix this up. If this is too much work, just leave it as is. Thanks! --- drivers/net/can/spi/mcp251x.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index a57da43680d8..6f888b771589 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -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);

@@ -1224,15 +1222,6 @@ 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; @@ -1252,7 +1241,6 @@ static int mcp251x_open(struct net_device *net)

out_free_wq: destroy_workqueue(priv->wq); -out_clean: free_irq(spi->irq, priv); mcp251x_hw_sleep(spi); out_close: @@ -1373,6 +1361,15 @@ 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 +1414,8 @@ 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 +1437,9 @@ 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);