On Wed, 8 May 2024, Christoph Fritz wrote:
> On Mon, 2024-05-06 at 19:24 +0300, Ilpo Järvinen wrote:
> > On Thu, 2 May 2024, 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.
> > > +static int lin_create_sysfs_id_files(struct net_device *ndev)
> > > +{
> > > + struct lin_device *ldev = netdev_priv(ndev);
> > > + struct kobj_attribute *attr;
> > > + int ret;
> > > +
> > > + for (int id = 0; id < LIN_NUM_IDS; id++) {
> > > + ldev->sysfs_entries[id].ldev = ldev;
> > > + attr = &ldev->sysfs_entries[id].attr;
> > > + attr->attr.name = kasprintf(GFP_KERNEL, "%02x", id);
> > > + if (!attr->attr.name)
> > > + return -ENOMEM;
> > > + attr->attr.mode = 0644;
> > > + attr->show = lin_identifier_show;
> > > + attr->store = lin_identifier_store;
> > > +
> > > + sysfs_attr_init(&attr->attr);
> > > + ret = sysfs_create_file(ldev->lin_ids_kobj, &attr->attr);
> > > + if (ret) {
> > > + kfree(attr->attr.name);
> > > + return -ENOMEM;
> > > + }
> > > + }
> > > +
> > > + return 0;
> > > +}
> >
> > Can you use .dev_groups instead ?
>
> I'm not sure where to attach this in this glue code here. Should I do a
> class_register() and add the .dev_groups there?
I guess struct class would be correct direction but I'm not sure if it's
viable in this case. It would avoid the need for custom sysfs setup code
if it's workable.
> > FWIW, this function doesn't do rollback when error occurs.
>
> OK, this issue can be fixed in revision v4.
>
> ...
> > > diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h
> > > index 02ec32d694742..51b0e2a7624e4 100644
> > > --- a/include/uapi/linux/can/netlink.h
> > > +++ b/include/uapi/linux/can/netlink.h
> > > @@ -103,6 +103,7 @@ struct can_ctrlmode {
> > > #define CAN_CTRLMODE_CC_LEN8_DLC 0x100 /* Classic CAN DLC option */
> > > #define CAN_CTRLMODE_TDC_AUTO 0x200 /* CAN transiver automatically calculates TDCV */
> > > #define CAN_CTRLMODE_TDC_MANUAL 0x400 /* TDCV is manually set up by user */
> >
> > BIT(x) is these days available also for uapi I think.
> >
> > > +#define CAN_CTRLMODE_LIN 0x800 /* LIN bus mode */
>
> So, should I use just BIT(11) for the new define, or should I also
> refactor the whole list while at it?
Either is fine for me.
--
i.
