Re: [PATCH] can: flexcan: fix timeout when set small bitrate

On 1/31/19 10:37 AM, Joakim Zhang wrote:

Current we can meet timeout issue when setting a small bitrate like 10000
as follows on i.MX6UL EVK board (ipg clock = 66MHZ, per clock = 30MHZ):
root@imx6ul7d:~# ip link set can0 up type can bitrate 10000
A link change request failed with some changes committed already.
Interface can0 may have been left with an inconsistent configuration, please check.
RTNETLINK answers: Connection timed out

It is caused by calling of flexcan_chip_unfreeze() timeout.

Originally the code is using usleep_range(10, 20) for unfreeze operation,
but the patch (8badd65 can: flexcan: avoid calling usleep_range from interrupt
context) changed it into udelay(10) which is only a half delay of before,
there're also some other delay changes.

After double to FLEXCAN_TIMEOUT_US to 100 can fix the issue.

Signed-off-by: Joakim Zhang <redacted>

Applied to linux-can

Tnx,
Marc

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