On 2/2/21 7:23 AM, Joakim Zhang wrote:
> 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 <[email protected]>
> ---
> 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);Please make use of existing functions like flexcan_chip_freeze(). regards, Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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