diff options
authorJoakim Zhang <qiangqing.zhang@nxp.com>2019-01-31 09:37:22 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-06-25 11:36:00 +0800
commit4ea81cc49c59007a23a54fcbe7ed3cc06eac2c6a (patch)
parentf6a2c8b3c24af782c94eda629a07016a129b81e4 (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>
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 2646faffd36e..6f265d2e647b 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -165,7 +165,7 @@
#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