From 2712625200ed69c642b9abc3a403830c4643364c Mon Sep 17 00:00:00 2001
From: Torin Cooper-Bennun <torin@maxiluxsystems.com>
Date: Fri, 26 Feb 2021 16:34:41 +0000
Subject: [PATCH] can: tcan4x5x: tcan4x5x_init(): fix initialization - clear
MRAM before entering Normal Mode
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 --git a/drivers/net/can/m_can/tcan4x5x-core.c b/drivers/net/can/m_can/tcan4x5x-core.c
index b7caec769ddb9..4147cecfbbd6d 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;
}
--
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