From: Greg Kroah-Hartman gregkh@linuxfoundation.org
From: Torin Cooper-Bennun torin@maxiluxsystems.com
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 mkl@pengutronix.de Signed-off-by: Torin Cooper-Bennun torin@maxiluxsystems.com Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/can/m_can/tcan4x5x.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/net/can/m_can/tcan4x5x.c +++ b/drivers/net/can/m_can/tcan4x5x.c @@ -326,14 +326,14 @@ static int tcan4x5x_init(struct m_can_cl 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; }