Re: [PATCH] watchdog: rn5t618: use proper module tables

[Andreas Kemnade <andreas@kemnade.info>]

Am Thu, 19 Sep 2024 13:02:55 +0200
schrieb Krzysztof Kozlowski <krzk@kernel.org>:

> On 19/09/2024 12:50, Andreas Kemnade wrote:
> > Am Wed, 18 Sep 2024 15:43:40 -0700
> > schrieb Guenter Roeck <linux@roeck-us.net>:
> >   
> >> On 9/18/24 14:29, Andreas Kemnade wrote:  
> >>> Avoid requiring MODULE_ALIASES by declaring proper device id
> >>> tables.
> >>>
> >>> Signed-off-by: Andreas Kemnade <andreas@kemnade.info>    
> >>
> >> This needs a better rationale. There are more than 40 watchdog
> >> drivers using MODULE_ALIAS. I would hate having to deal with 40+
> >> patches just for cosmetic reasons, not counting the thousands of
> >> instances of MODULE_ALIAS in the kernel, including the more than
> >> 1,000 instances of "MODULE_ALIAS.*platform:".
> >>  
> > basically reviewers were arguing against patches from me bringing in
> > MODULE_ALIASES. So I decided to clean up a bit in my backyard. Not
> > sure whether such things could by done by coccinelle but at least
> > it could be tested via output of modinfo.
> > 
> > This is one example for such a patch:
> > https://lore.kernel.org/linux-clk/119f56c8-5f38-eb48-7157-6033932f0430@linaro.org/
> >   
> 
> There are multiple aspects here:
> 1. People (including me) copy code which they do no understand. Or
> without really digging into it, because they do not have time. They
> just copy it, regardless whether the code is necessary or not.
> MODULE_ALIAS is one of such examples. It got copied to new drivers
> just because some other driver had it.
> 
and copy nowadays unaccepted design patterns. Probably best to look at
the newest example.

> 2. MODULE_ALIAS creates basically ABI - some user-space might depend
> on it, so removal might affect user. I think I was not dropping it
> from the drivers in cases it would actually drop an alias. I was only
> dropping duplicated aliases. That's not the case here, I believe.
> 
> 3. MODULE_ALIAS scales poor. I believe proper xxx_device_id table is
> better.
> 
> 4. But it does not mean that one single line - MODULE_ALIAS - should
> be replaced in existing drivers into full-blown ID table. I think I
> never proposed such patches for existing drivers. Why? Because if
> there was no such need so far, means there were no scalability issues.
> 
Thanks for the long explanation.

Regards,
Andreas