> -----Original Message----- > From: Joakim Zhang > Sent: Thursday, January 31, 2019 5:37 PM > To: mkl@xxxxxxxxxxxxxx; linux-can@xxxxxxxxxxxxxxx > Cc: wg@xxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>; Joakim > Zhang <qiangqing.zhang@xxxxxxx> > Subject: [PATCH] can: flexcan: fix timeout when set small bitrate > > 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> Reviewed-by: Dong Aisheng <aisheng.dong@xxxxxxx> Regards Dong Aisheng
