On Mon, Jun 13, 2022 at 9:37 AM Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> wrote:
>
> On 12.06.2022 23:39:27, Dario Binacchi wrote:
> > It extends the protocol to receive the adapter CAN state changes
> > (warning, busoff, etc.) and forward them to the netdev upper levels.
> >
> > Signed-off-by: Dario Binacchi <dario.binacchi@xxxxxxxxxxxxxxxxxxxx>
> >
> > ---
> >
> > Changes in v3:
> > - Drop the patch "can: slcan: simplify the device de-allocation".
> > - Add the patch "can: netlink: dump bitrate 0 if can_priv::bittiming.bitrate is -1U".
> >
> > Changes in v2:
> > - Continue error handling even if no skb can be allocated.
> >
> > drivers/net/can/slcan/slcan-core.c | 66 ++++++++++++++++++++++++++++++
> > 1 file changed, 66 insertions(+)
> >
> > diff --git a/drivers/net/can/slcan/slcan-core.c b/drivers/net/can/slcan/slcan-core.c
> > index 48077edb9497..5ba1c141f942 100644
> > --- a/drivers/net/can/slcan/slcan-core.c
> > +++ b/drivers/net/can/slcan/slcan-core.c
> > @@ -78,6 +78,9 @@ MODULE_PARM_DESC(maxdev, "Maximum number of slcan interfaces");
> > #define SLC_CMD_LEN 1
> > #define SLC_SFF_ID_LEN 3
> > #define SLC_EFF_ID_LEN 8
> > +#define SLC_STATE_LEN 1
> > +#define SLC_STATE_BE_RXCNT_LEN 3
> > +#define SLC_STATE_BE_TXCNT_LEN 3
> >
> > struct slcan {
> > struct can_priv can;
> > @@ -175,6 +178,67 @@ int slcan_enable_err_rst_on_open(struct net_device *ndev, bool on)
> > * STANDARD SLCAN DECAPSULATION *
> > ************************************************************************/
> >
> > +static void slc_bump_state(struct slcan *sl)
> > +{
> > + struct net_device *dev = sl->dev;
> > + struct sk_buff *skb;
> > + struct can_frame *cf;
> > + char *cmd = sl->rbuff;
> > + u32 rxerr, txerr;
> > + enum can_state state, rx_state, tx_state;
> > +
> > + if (*cmd != 's')
> > + return;
>
> Checked by the caller?
>
> > +
> > + cmd += SLC_CMD_LEN;
> > + switch (*cmd) {
> > + case 'a':
> > + state = CAN_STATE_ERROR_ACTIVE;
> > + break;
> > + case 'w':
> > + state = CAN_STATE_ERROR_WARNING;
> > + break;
> > + case 'p':
> > + state = CAN_STATE_ERROR_PASSIVE;
> > + break;
> > + case 'f':
> > + state = CAN_STATE_BUS_OFF;
> > + break;
> > + default:
> > + return;
> > + }
> > +
> > + if (state == sl->can.state)
> > + return;
> > +
> > + cmd += SLC_STATE_BE_RXCNT_LEN + 1;
>
> Have you checked that you have received that much data?
>
> > + cmd[SLC_STATE_BE_TXCNT_LEN] = 0;
> > + if (kstrtou32(cmd, 10, &txerr))
> > + return;
> > +
> > + *cmd = 0;
> > + cmd -= SLC_STATE_BE_RXCNT_LEN;
> > + if (kstrtou32(cmd, 10, &rxerr))
> > + return;
>
> Why do you parse TX first and then RX?
Since adding the end-of-string character to the counter to be decoded
invalidates the next one.
If I had started from the rx counter, I would have found the
transmission counter always at 0.
Thanks and regards,
Dario
>
> > +
> > + skb = alloc_can_err_skb(dev, &cf);
> > +
> > + if (skb) {
> > + cf->data[6] = txerr;
> > + cf->data[7] = rxerr;
> > + }
> > +
> > + tx_state = txerr >= rxerr ? state : 0;
> > + rx_state = txerr <= rxerr ? state : 0;
> > + can_change_state(dev, skb ? cf : NULL, tx_state, rx_state);
>
> alloc_can_err_skb() set cf to NULL if no skb can be allocated.
>
> > +
> > + if (state == CAN_STATE_BUS_OFF)
> > + can_bus_off(dev);
> > +
> > + if (skb)
> > + netif_rx(skb);
> > +}
> > +
> > static void slc_bump_err(struct slcan *sl)
> > {
> > struct net_device *dev = sl->dev;
> > @@ -378,6 +442,8 @@ static void slc_bump(struct slcan *sl)
> > return slc_bump_frame(sl);
> > case 'e':
> > return slc_bump_err(sl);
> > + case 's':
> > + return slc_bump_state(sl);
> > default:
> > return;
> > }
> > --
> > 2.32.0
> >
> >
>
> 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 |
--
Dario Binacchi
Embedded Linux Developer
dario.binacchi@xxxxxxxxxxxxxxxxxxxx
__________________________________
Amarula Solutions SRL
Via Le Canevare 30, 31100 Treviso, Veneto, IT
T. +39 042 243 5310
info@xxxxxxxxxxxxxxxxxxxx
www.amarulasolutions.com
