Re: [PATCH v5 2/7] can: bittiming: allow TDC{V,O} to be zero and add can_tdc_const::tdc{v,o,f}_min

From: Vincent MAILHOL
Date: Mon Aug 16 2021 - 21:13:30 EST


Hi Marc,

This patch fixes the bug you just encountered: having both TDC_AUTO
and TDC_MANUAL set at the same time. I also cleaned all garbage
data in struct can_tdc because that was trivial.

This patch is meant to be squashed into:
commit ca7200319a90 ("can: netlink: add interface for CAN-FD
Transmitter Delay Compensation (TDC)")

For now, I am just sharing it here so that you can continue your
testing. I will resend the full series after we finish current
ongoing discussion.

Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
---
drivers/net/can/dev/netlink.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c
index f05745c96b9c..d8cefe7d354c 100644
--- a/drivers/net/can/dev/netlink.c
+++ b/drivers/net/can/dev/netlink.c
@@ -204,6 +204,7 @@ static int can_changelink(struct net_device *dev,
struct nlattr *tb[],
}
}

+ priv->ctrlmode &= ~CAN_CTRLMODE_TDC_MASK;
if (data[IFLA_CAN_CTRLMODE]) {
struct can_ctrlmode *cm;
u32 ctrlstatic;
@@ -239,8 +240,6 @@ static int can_changelink(struct net_device *dev,
struct nlattr *tb[],
dev->mtu = CAN_MTU;
memset(&priv->data_bittiming, 0,
sizeof(priv->data_bittiming));
- memset(&priv->tdc, 0, sizeof(priv->tdc));
- priv->ctrlmode &= ~CAN_CTRLMODE_TDC_MASK;
}

tdc_mask = cm->mask & CAN_CTRLMODE_TDC_MASK;
@@ -326,6 +325,7 @@ static int can_changelink(struct net_device *dev,
struct nlattr *tb[],
priv->termination = termval;
}

+ memset(&priv->tdc, 0, sizeof(priv->tdc));
if (data[IFLA_CAN_TDC]) {
/* Use the provided TDC parameters */
err = can_tdc_changelink(dev, data[IFLA_CAN_TDC], extack);
--
2.31.1