[PATCH 4.9 83/87] can: ifi: Fix transmitter delay calculation

From: Greg Kroah-Hartman
Date: Mon Nov 13 2017 - 08:03:16 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Marek Vasut <marex@xxxxxxx>

commit 4f7116757b4bd99e4ef2636c7d957a6d63035d11 upstream.

The CANFD transmitter delay calculation formula was updated in the
latest software drop from IFI and improves the behavior of the IFI
CANFD core during bitrate switching. Use the new formula to improve
stability of the CANFD operation.

Signed-off-by: Marek Vasut <marex@xxxxxxx>
Cc: Markus Marb <markus@xxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/can/ifi_canfd/ifi_canfd.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/net/can/ifi_canfd/ifi_canfd.c
+++ b/drivers/net/can/ifi_canfd/ifi_canfd.c
@@ -670,9 +670,9 @@ static void ifi_canfd_set_bittiming(stru
priv->base + IFI_CANFD_FTIME);

/* Configure transmitter delay */
- tdc = (dbt->brp * (dbt->phase_seg1 + 1)) & IFI_CANFD_TDELAY_MASK;
- writel(IFI_CANFD_TDELAY_EN | IFI_CANFD_TDELAY_ABS | tdc,
- priv->base + IFI_CANFD_TDELAY);
+ tdc = dbt->brp * (dbt->prop_seg + dbt->phase_seg1);
+ tdc &= IFI_CANFD_TDELAY_MASK;
+ writel(IFI_CANFD_TDELAY_EN | tdc, priv->base + IFI_CANFD_TDELAY);
}

static void ifi_canfd_set_filter(struct net_device *ndev, const u32 id,