From b7049b6156ce417dff30bb411bb56b534534ce79 Mon Sep 17 00:00:00 2001 From: Torin Cooper-Bennun Date: Fri, 26 Feb 2021 16:34:41 +0000 Subject: [PATCH] can: tcan4x5x: tcan4x5x_init(): fix initialization - clear MRAM before entering Normal Mode commit 2712625200ed69c642b9abc3a403830c4643364c upstream. 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 Signed-off-by: Torin Cooper-Bennun Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/m_can/tcan4x5x.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/can/m_can/tcan4x5x.c b/drivers/net/can/m_can/tcan4x5x.c index 1f8710b35c6d..32cb479fe6ac 100644 --- a/drivers/net/can/m_can/tcan4x5x.c +++ b/drivers/net/can/m_can/tcan4x5x.c @@ -325,14 +325,14 @@ 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; }