On 12/19/18 7:39 PM, Manfred Schlaegl wrote:

This reverts commit 7da11ba5c5066dadc2e96835a6233d56d7b7764a.

After introduction of this change we encountered following new error
message on various i.MX plattforms (flexcan)
flexcan 53fc8000.can can0: __can_get_echo_skb: BUG! Trying to echo non
existing skb: can_priv::echo_skb[0]

Doh! I should have tested more extensive. Sorry.

The introduction of the message was a mistake because
priv->echo_skb[idx] = NULL is a perfectly valid in following case:
If CAN_RAW_LOOPBACK is disabled (setsockopt) in applications, the
pkt_type of the tx skb's given to can_put_echo_skb is set to
PACKET_LOOPBACK. In this case can_put_echo_skb will not set
priv->echo_skb[idx]. It is therefore kept NULL.

(As additional argument for revert: The order of check and usage of idx
was changed. idx is used to access an array element before checking it's
boundaries)

Signed-off-by: Manfred Schlaegl <redacted>

Applied to linux-can.

Tnx,
Marc

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