Re: [PATCH] char: applicom: remove low-quality, unused driver

[Arnd Bergmann]

On Sun, May 3, 2026, at 05:58, Ethan Nelson-Moore wrote:
> The applicom driver supports PCI Profibus cards from Applicom, later
> acquired by Molex. It has severe coding style issues and has attracted
> a number of bug and security fixes over the years, despite the fact
> that no one appears to be using it. It was broken from at least the
> beginning of Git history (Linux 2.6.12-rc2 in April 2005) until October
> 2008, when a fatal bug was fixed in commit bc20589bf1c6 ("applicom.c:
> fix apparently-broken code in do_ac_read()"). In the commit message,
> the author commented that no one they knew was able to test the change.
> Since then, there have been no commits that indicate the driver is
> being used. Later PCI and PCI-Express Applicom Profibus cards only
> officially support Windows [1], and even the PCI-Express cards have
> been discontinued [2]. Given all these factors, remove the driver to
> reduce future maintenance workload.
>
> [1] 
> https://www.sarcitalia.it/file_upload/prodotti//PCIE1500S7_PFB_987651-3769_0876250001505823933.pdf
> [2] 
> https://us.rs-online.com/product/molex-woodhead-brad/112011-5026/70631928/
>
> Signed-off-by: Ethan Nelson-Moore <enelsonmoore@xxxxxxxxx>

I recently looked at this when another fix came in and came to
similar conclusions, but at the wasn't sure if any users remain:

https://lore.kernel.org/all/5c4965c8-dcec-4faf-bd87-19ca7665fedc@xxxxxxxxxxxxxxxx/

Let's go with your patch now. If users do remain, they should
be able to either just revert the removal locally, or work
on reintroducing an improved driver.

Acked-by: Arnd Bergmann <arnd@xxxxxxxx>