Re: [PATCH net-next v2 3/5] devlink: Allow set specific ops callbacks dynamically

On Tue, 5 Oct 2021 22:15:40 +0300 Leon Romanovsky wrote:

On Tue, Oct 05, 2021 at 11:32:13AM -0700, Jakub Kicinski wrote:

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On Tue, 5 Oct 2021 10:32:45 +0300 Leon Romanovsky wrote:  

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It is impossible, devlink_register() is part of .probe() flow and if it
wasn't called -> probe didn't success -> net_device doesn't exist.  

Are you talking about reality or the bright future brought by auxbus?  

I looked on all the drivers which called to devlink_alloc() which is
starting point before devlink_register(). All of them used it in the
probe. My annotation patch checks that too.

https://lore.kernel.org/linux-rdma/f65772d429d2c259bbc18cf5b1bbe61e39eb7081.1633284302.git.leonro@nvidia.com/T/#u (local)

So IMHO, it is reality.

You say that yet below you admit flashing is broken :/

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We are not having net_device without "connected" device beneath, aren't we?

At least drivers that I checked are not prepared at all to handle call
to devlink->ops.flash_update() if they didn't probe successfully.  

Last time I checked you moved the devlink_register() at the end of
probe which for all no-auxbus drivers means after register_netdev().  

I need to add a check of if(devlink_register) inside devlink_compat_flash_update().

... and the workarounds start to pile up.

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I don't like it. If you're feeling strongly please gather support of
other developers. Right now it's my preference against yours. I don't
even see you making arguments that your approach is better, just that
mine is not perfect and requires some similar changes.  

I have an idea of how to keep static ops and allow devlink_set_ops()
like functionality.

What about if I group ops by some sort of commonalities?

In my case, it will be devlink_reload_ops, which will include reload
relevant callbacks and provide devlink_set_reload_ops() wrapper to set
them?

It will ensure that all pointers are const without need to have feature
bits.

I don't understand why you keep pushing the op reassignment.