diff mbox series

[net,6/6] can: tcan4x5x: tcan4x5x_init(): fix initialization - clear MRAM before entering Normal Mode

Message ID 20210301112100.197939-7-mkl@pengutronix.de
State New
Headers show
Series [net,1/6] can: flexcan: assert FRZ bit in flexcan_chip_freeze() | expand

Commit Message

Marc Kleine-Budde March 1, 2021, 11:21 a.m. UTC 
From: Torin Cooper-Bennun <torin@maxiluxsystems.com>

This patch prevents a potentially destructive race condition. The
device is fully operational on the bus after entering Normal Mode, so
zeroing the MRAM after entering this mode may lead to loss of
information, e.g. new received messages.

This patch fixes the problem by first initializing the MRAM, then
bringing the device into Normale Mode.

Fixes: 5443c226ba91 ("can: tcan4x5x: Add tcan4x5x driver to the kernel")
Link: https://lore.kernel.org/r/20210226163440.313628-1-torin@maxiluxsystems.com
Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Torin Cooper-Bennun <torin@maxiluxsystems.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/m_can/tcan4x5x-core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/can/m_can/tcan4x5x-core.c b/drivers/net/can/m_can/tcan4x5x-core.c
index b7caec769ddb..4147cecfbbd6 100644
--- a/drivers/net/can/m_can/tcan4x5x-core.c
+++ b/drivers/net/can/m_can/tcan4x5x-core.c
@@ -237,14 +237,14 @@  static int tcan4x5x_init(struct m_can_classdev *cdev)
 	if (ret)
 		return ret;
 
+	/* Zero out the MCAN buffers */
+	m_can_init_ram(cdev);
+
 	ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
 				 TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_NORMAL);
 	if (ret)
 		return ret;
 
-	/* Zero out the MCAN buffers */
-	m_can_init_ram(cdev);
-
 	return ret;
 }