diff options
| author | Joakim Zhang <qiangqing.zhang@nxp.com> | 2019-01-31 09:37:22 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-10 09:56:33 +0200 |
| commit | b4fd1ed2b17217611329d6b633bb3aff33f257c0 (patch) | |
| tree | 6b548e30f458902ff34778cb55eb74e593e815b8 /drivers | |
| parent | d38cac353bc5d3d056906c77ca27326b0b6c46bc (diff) | |
can: flexcan: fix timeout when set small bitrate
commit 247e5356a709eb49a0d95ff2a7f07dac05c8252c upstream.
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.
Meanwhile, Rasmus Villemoes reported that even with a timeout of 100,
flexcan_probe() fails on the MPC8309, which requires a value of at least
140 to work reliably. 250 works for everyone.
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/can/flexcan.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index 47f43bdecd51..baef09b9449f 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -171,7 +171,7 @@ #define FLEXCAN_MB_CNT_LENGTH(x) (((x) & 0xf) << 16) #define FLEXCAN_MB_CNT_TIMESTAMP(x) ((x) & 0xffff) -#define FLEXCAN_TIMEOUT_US (50) +#define FLEXCAN_TIMEOUT_US (250) /* FLEXCAN hardware feature flags * |