Merge tag 'linux-can-fixes-for-5.13-20210506' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2021-05-06

The first two patches target the mcp251xfd driver. Dan Carpenter's
patch fixes a NULL pointer dereference in the probe function's error
path. A patch by me adds the missing can_rx_offload_del() in error
path of the probe function.

Frieder Schrempf contributes a patch for the mcp251x driver, the patch
fixes the resume from sleep before interface was brought up.

The last patch is by me and fixes a race condition in the TX path of
the m_can driver for peripheral (SPI) based m_can cores.

* tag 'linux-can-fixes-for-5.13-20210506' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can:
  can: m_can: m_can_tx_work_queue(): fix tx_skb race condition
  can: mcp251x: fix resume from sleep before interface was brought up
  can: mcp251xfd: mcp251xfd_probe(): add missing can_rx_offload_del() in error path
  can: mcp251xfd: mcp251xfd_probe(): fix an error pointer dereference in probe
====================

Link: https://lore.kernel.org/r/20210506074015.1300591-1-mkl@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 25 insertions, 21 deletions

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 34073cd077e4..3cf6de21d19c 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -1562,6 +1562,8 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
 	int i;
 	int putidx;
 
+	cdev->tx_skb = NULL;
+
 	/* Generate ID field for TX buffer Element */
 	/* Common to all supported M_CAN versions */
 	if (cf->can_id & CAN_EFF_FLAG) {
@@ -1678,7 +1680,6 @@ static void m_can_tx_work_queue(struct work_struct *ws)
 						   tx_work);
 
 	m_can_tx_handler(cdev);
-	cdev->tx_skb = NULL;
 }
 
 static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index 492f1bcb0516..173c6614086f 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);
 
@@ -1224,24 +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);
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
index 970dc570e7a5..e0ae00e34c7b 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
@@ -2885,8 +2885,8 @@ static int mcp251xfd_probe(struct spi_device *spi)
 
 	clk = devm_clk_get(&spi->dev, NULL);
 	if (IS_ERR(clk))
-		dev_err_probe(&spi->dev, PTR_ERR(clk),
-			      "Failed to get Oscillator (clock)!\n");
+		return dev_err_probe(&spi->dev, PTR_ERR(clk),
+				     "Failed to get Oscillator (clock)!\n");
 	freq = clk_get_rate(clk);
 
 	/* Sanity check */
@@ -2986,10 +2986,12 @@ static int mcp251xfd_probe(struct spi_device *spi)
 
 	err = mcp251xfd_register(priv);
 	if (err)
-		goto out_free_candev;
+		goto out_can_rx_offload_del;
 
 	return 0;
 
+ out_can_rx_offload_del:
+	can_rx_offload_del(&priv->offload);
  out_free_candev:
 	spi->max_speed_hz = priv->spi_max_speed_hz_orig;