Re: of alloc_canxl_skb

[Dr. David Alan Gilbert]

* Oliver Hartkopp (socketcan@xxxxxxxxxxxx) wrote:
> Hi David,

Hi Oliver,

> On 13.09.24 16:03, Dr. David Alan Gilbert wrote:
> 
> >    I'm doing some deadcode hunting and noticed that
> > 
> >    alloc_canxl_skb in drivers/net/can/dev/skb.c
> > 
> > looks unused in the main kernel tree; is that expected?
> > I see it was added back in 2022 by
> >    fb08cba12b52 ("can: canxl: update CAN infrastructure for CAN XL frames")
> > 
> > I know almost exactly nothing about CAN, so I thought it best
> > to ask!
> 
> I created some slides so that you can get an introduction to the different
> CAN protocols CAN CC (aka Classical CAN), CAN FD and CAN XL:
> 
> https://github.com/linux-can/can-doc/tree/master/presentations

Thanks!

> The introduction of the CAN XL support lead to some clean up and rework also
> for the former alloc_can_skb() and alloc_canfd_skb() helpers.
> 
> The function is currently not in use in net/can/raw.c as it is only needed
> when a CAN XL frame is received from read hardware. But the patch also
> contains the definition of ETH_P_CANXL to already handle CAN XL frames
> properly inside the Linux kernel and e.g. for WireShark 4.4.
> 
> There are currently some CAN XL IP cores in development (see attached
> picture with an FPGA based IP core) and I am working on the kernel
> infrastructure (e.g. bitrate configuration enhancements) on this board. So
> alloc_canxl_skb() is already in use on my desk and there will be some more
> stuff showing up soon ;-)

OK, great - I won't try and deadcode it then!

Thanks again for the reply,

Dave


> Best regards,
> Oliver


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