On Tue, May 04, 2021 at 06:01:48PM +0200, Schrempf Frieder wrote:
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.
AFAIU the IRQ is freed at ->ndo_stop() which is guaranteed to be called before ->remove(). If it's the case, we are fine.
FWIW, Reviewed-by: Andy Shevchenko andriy.shevchenko@linux.intel.com
Fixes: 8ce8c0abcba3 ("can: mcp251x: only reset hardware as required") Cc: stable@vger.kernel.org Signed-off-by: Frieder Schrempf frieder.schrempf@kontron.de
drivers/net/can/spi/mcp251x.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-)
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index a57da43680d8..42e8e5791c9f 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;
@@ -1373,6 +1362,15 @@ 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 +1415,8 @@ 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 +1438,9 @@ 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); -- 2.25.1