Messages in this thread | | | Date | Mon, 25 Jul 2022 15:25:14 +0200 | From | Marc Kleine-Budde <> | Subject | Re: [PATCH v2 0/6] can: slcan: extend supported features (step 2) |
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On 25.07.2022 08:54:13, Dario Binacchi wrote: > With this series I try to finish the task, started with the series [1], > of completely removing the dependency of the slcan driver from the > userspace slcand/slcan_attach applications. > > The series, however, still lacks a patch for sending the bitrate setting > command to the adapter: > > slcan_attach -b <btr> <dev> > > Without at least this patch the task cannot be considered truly completed. > > The idea I got is that this can only happen through the ethtool API. > Among the various operations made available by this interface I would > have used the set_regs (but only the get_regs has been developed), or, > the set_eeprom, even if the setting would not be stored in an eeprom. > IMHO it would take a set_regs operation with a `struct ethtool_wregs' > parameter similar to `struct ethtool_eeprom' without the magic field:
This doesn't feel right.
> struct ethtool_wregs { > __u32 cmd; > __u32 offset; > __u32 len; > __u8 data[0]; > }; > > But I am not the expert and if there was an alternative solution already > usable, it would be welcome.
Have a look at the get/set_tunable() callback:
| https://elixir.bootlin.com/linux/latest/source/include/linux/ethtool.h#L575
You probably have to add a new tunable. Here you'll find the people and commits that changed the tunable:
| https://github.com/torvalds/linux/blame/master/include/uapi/linux/ethtool.h#L229
It's usually worth including them in an RFC patch series where you add a new tunable and make use of it in the slcan driver.
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 | [unhandled content-type:application/pgp-signature] | |