On Sat, 2024-05-04 at 13:49 +0100, Simon Horman wrote:
> On Thu, May 02, 2024 at 09:55:23AM +0200, Christoph Fritz wrote:
> > This patch adds a LIN (local interconnect network) bus abstraction on
> > top of CAN. It is a glue driver adapting CAN on one side while offering
> > LIN abstraction on the other side. So that upcoming LIN device drivers
> > can make use of it.
> >
> > Tested-by: Andreas Lauser <andreas.lauser@xxxxxxxxxxxxxxxxx>
> > Signed-off-by: Christoph Fritz <christoph.fritz@xxxxxxxxx>
>
> ...
>
> > diff --git a/drivers/net/can/lin.c b/drivers/net/can/lin.c
>
> ...
>
> > +struct lin_device *register_lin(struct device *dev,
> > + const struct lin_device_ops *ldops)
> > +{
> > + struct net_device *ndev;
> > + struct lin_device *ldev;
> > + int ret;
> > +
> > + if (!ldops || !ldops->ldo_tx || !ldops->update_bitrate ||
> > + !ldops->ldo_open || !ldops->ldo_stop) {
> > + netdev_err(ndev, "missing mandatory lin_device_ops\n");
>
> Hi Christoph,
Hi Simon
> The line above uses ndev, but ndev is not initialised
> until a few lines further down.
>
> Flagged by Smatch.
Despite netdev_err() checks validity of ndev, I agree with Smatch: In
upcoming v4 I'll use dev_err() here instead.
> > + return ERR_PTR(-EINVAL);
> > + }
> > +
> > + ndev = alloc_candev(sizeof(struct lin_device), 1);
> > + if (!ndev)
> > + return ERR_PTR(-ENOMEM);
> > +
> > + ldev = netdev_priv(ndev);
> > +
> > + ldev->ldev_ops = ldops;
> > + ndev->netdev_ops = &lin_netdev_ops;
> > + ndev->flags |= IFF_ECHO;
> > + ndev->mtu = CANFD_MTU;
> > + ldev->can.bittiming.bitrate = LIN_DEFAULT_BAUDRATE;
> > + ldev->can.ctrlmode = CAN_CTRLMODE_LIN;
> > + ldev->can.ctrlmode_supported = 0;
> > + ldev->can.bitrate_const = lin_bitrate;
> > + ldev->can.bitrate_const_cnt = ARRAY_SIZE(lin_bitrate);
> > + ldev->can.do_set_bittiming = lin_set_bittiming;
> > + ldev->ndev = ndev;
> > + ldev->dev = dev;
> > +
> > + SET_NETDEV_DEV(ndev, dev);
> > +
> > + ret = lin_set_bittiming(ndev);
> > + if (ret) {
> > + netdev_err(ndev, "set bittiming failed\n");
> > + goto exit_candev;
> > + }
> > +
> > + ret = register_candev(ndev);
> > + if (ret)
> > + goto exit_candev;
> > +
> > + ldev->lin_ids_kobj = kobject_create_and_add("lin_ids", &ndev->dev.kobj);
> > + if (!ldev->lin_ids_kobj) {
> > + netdev_err(ndev, "Failed to create sysfs directory\n");
> > + ret = -ENOMEM;
> > + goto exit_unreg;
> > + }
> > +
> > + ret = lin_create_sysfs_id_files(ndev);
> > + if (ret) {
> > + netdev_err(ndev, "Failed to create sysfs entry: %d\n", ret);
> > + goto exit_kobj_put;
> > + }
> > +
> > + /* Using workqueue as tx over USB/SPI/... may sleep */
> > + ldev->wq = alloc_workqueue(dev_name(dev), WQ_FREEZABLE | WQ_MEM_RECLAIM,
> > + 0);
> > + if (!ldev->wq)
> > + goto exit_rm_files;
>
> The goto above will result in: return ERR_PTR(ret)
> But ret is 0 here. Should it be set to a negative error value?
>
> Also flagged by Smatch.
OK, will get an
ret = -ENOMEM;
>
> > +
> > + INIT_WORK(&ldev->tx_work, lin_tx_work_handler);
> > +
> > + netdev_info(ndev, "LIN initialized.\n");
> > +
> > + return ldev;
> > +
> > +exit_rm_files:
> > + lin_remove_sysfs_id_files(ndev);
> > +exit_kobj_put:
> > + kobject_put(ldev->lin_ids_kobj);
> > +exit_unreg:
> > + unregister_candev(ndev);
> > +exit_candev:
> > + free_candev(ndev);
> > + return ERR_PTR(ret);
> > +}
> > +EXPORT_SYMBOL_GPL(register_lin);
>
> ...
Thanks
-- Christoph
