[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date: Tue, 2 Feb 2021 14:23:50 +0800
From: Joakim Zhang <qiangqing.zhang@....com>
To: mkl@...gutronix.de, linux-can@...r.kernel.org
Cc: netdev@...r.kernel.org, linux-imx@....com
Subject: [PATCH linux-can] can: flexcan: enable RX FIFO after FRZ/HALT valid
RX FIFO enable failed could happen when do system reboot stress test,
one customer reports failure rate is about 50%.
[ 0.303958] flexcan 5a8d0000.can: 5a8d0000.can supply xceiver not found, using dummy regulator
[ 0.304281] flexcan 5a8d0000.can (unnamed net_device) (uninitialized): Could not enable RX FIFO, unsupported core
[ 0.314640] flexcan 5a8d0000.can: registering netdev failed
[ 0.320728] flexcan 5a8e0000.can: 5a8e0000.can supply xceiver not found, using dummy regulator
[ 0.320991] flexcan 5a8e0000.can (unnamed net_device) (uninitialized): Could not enable RX FIFO, unsupported core
[ 0.331360] flexcan 5a8e0000.can: registering netdev failed
[ 0.337444] flexcan 5a8f0000.can: 5a8f0000.can supply xceiver not found, using dummy regulator
[ 0.337716] flexcan 5a8f0000.can (unnamed net_device) (uninitialized): Could not enable RX FIFO, unsupported core
[ 0.348117] flexcan 5a8f0000.can: registering netdev failed
RX FIFO should be enabled after the FRZ/HALT are valid. But the current
code set RX FIFO enable and FRZ/HALT at the same time.
Fixes: e955cead03117 ("CAN: Add Flexcan CAN controller driver")
Signed-off-by: Joakim Zhang <qiangqing.zhang@....com>
---
drivers/net/can/flexcan.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 038fe1036df2..8ee9fa2f4161 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -1803,6 +1803,7 @@ static int register_flexcandev(struct net_device *dev)
{
struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->regs;
+ unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
u32 reg, err;
err = flexcan_clks_enable(priv);
@@ -1825,10 +1826,19 @@ static int register_flexcandev(struct net_device *dev)
if (err)
goto out_chip_disable;
- /* set freeze, halt and activate FIFO, restrict register access */
+ /* set freeze, halt and polling the freeze ack */
reg = priv->read(®s->mcr);
- reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT |
- FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
+ reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT;
+ priv->write(reg, ®s->mcr);
+
+ while (timeout-- && !(priv->read(®s->mcr) & FLEXCAN_MCR_FRZ_ACK))
+ udelay(100);
+
+ if (!(priv->read(®s->mcr) & FLEXCAN_MCR_FRZ_ACK))
+ return -ETIMEDOUT;
+
+ /* Activate FIFO, restrict register access */
+ reg |= FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
priv->write(reg, ®s->mcr);
/* Currently we only support newer versions of this core
--
2.17.1
Powered by blists - more mailing lists