linux-kernel - Re: [PATCH 00/23] Floppy driver cleanups

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Message-ID: <20200331110136.GB24562@1wt.eu>
Date:   Tue, 31 Mar 2020 13:01:36 +0200
From:   Willy Tarreau <w@....eu>
To:     Christoph Hellwig <hch@...radead.org>
Cc:     Denis Efremov <efremov@...ux.com>, Jens Axboe <axboe@...nel.dk>,
        linux-block@...r.kernel.org, linux-kernel@...r.kernel.org,
        "David S. Miller" <davem@...emloft.net>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Geert Uytterhoeven <geert@...ux-m68k.org>,
        Helge Deller <deller@....de>, Ian Molton <spyro@....com>,
        Ivan Kokshaysky <ink@...assic.park.msu.ru>,
        Matt Turner <mattst88@...il.com>,
        Richard Henderson <rth@...ddle.net>,
        Russell King <linux@...linux.org.uk>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>, x86@...nel.org
Subject: Re: [PATCH 00/23] Floppy driver cleanups

Hi Christoph,

On Tue, Mar 31, 2020 at 03:10:19AM -0700, Christoph Hellwig wrote:
> Hi Willy,
> 
> given that you are actively maintaining the floppy driver now,

No no no I'm not! Denis is :-) Really, I mean I just proposed some help
to clean up this mess after being tricked into not believing a bug report
just because the code was too confusing.

> any
> chance I could trick you into proper highmem handling?  I've been trying
> to phase out block layer bounce buffering, and any help from a competent
> maintainer to move their drivers to properly support highmem by kmapping
> for PIO/MMIO I/O would be very helpful.

I'm not sure what this implies regarding this code, to be honest. It's
very tricky and implements sort of a state machine using function pointers
within its interrupt handler so you never know exactly what accesses what,
and quite a part of it remains obscure to me :-/  I can accept to help, I
can even run tests since I still have running hardware, but I'd at least
need some guidance. And probably Denis would know better than me there.
Also I doubt we'd get sufficient testing on less common archs. While I
do have sparc64/parisc/alpha available, I haven't booted a recent kernel
on any of them for a while (2.4 used to be the last ones), and I'm not
sure it's reasonable to go into such changes without proper testing.

What do you think ?

Willy