On 03.03.2021 09:23:13, Dario Binacchi wrote:
[...]
> > > @@ -1205,17 +1203,31 @@ static int c_can_close(struct net_device *dev)
> > > return 0;
> > > }
> > >
> > > -struct net_device *alloc_c_can_dev(void)
> > > +struct net_device *alloc_c_can_dev(int msg_obj_num)
> > > {
> > > struct net_device *dev;
> > > struct c_can_priv *priv;
> > > + int msg_obj_tx_num = msg_obj_num / 2;
> >
> > IMO, a bigger tx queue is not usefull.
> > A bigger rx queue however is.
>
> This would not be good for my application. I think it really depends
> on the type of application. We can probably say that being able to
> size rx/tx queue would be a useful feature.Ok. There is an ethtool interface to configure the size of the RX and TX queues. In ethtool it's called the RX/TX "ring" size and you can get it via the -g parameter, e.g. here for by Ethernet interface: | $ ethtool -g enp0s25 | Ring parameters for enp0s25: | Pre-set maximums: | RX: 4096 | RX Mini: n/a | RX Jumbo: n/a | TX: 4096 | Current hardware settings: | RX: 256 | RX Mini: n/a | RX Jumbo: n/a | TX: 256 If I understand correctly patch 6 has some assumptions that RX and TX are max 32. To support up to 64 RX objects, you have to convert: - u32 -> u64 - BIT() -> BIT_ULL() - GENMASK() -> GENMASK_ULL() The register access has to be converted, too. For performance reasons you want to do as least as possible. Which is probably the most complicated. In the flexcan driver I have a similar problem. The driver keeps masks, which mailboxes are RX and which TX and I added wrapper functions to minimize IO access: https://elixir.bootlin.com/linux/v5.11/source/drivers/net/can/flexcan.c#L904 This should to IMHO into patch 6. Adding the ethtool support and making the rings configurable would be a separate patch. 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 |
signature.asc
Description: PGP signature
