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

From: Marc Kleine-Budde
Date: Wed Feb 27 2019 - 06:06:36 EST


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 <qiangqing.zhang@xxxxxxx>

Applied to linux-can

Tnx,
Marc

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