From: Michael Schmitz <schmitzmic@gmail.com>
To: Arnd Bergmann <arnd@kernel.org>, Finn Thain <fthain@telegraphics.com.au>
Cc: "Song Bao Hua (Barry Song)" <song.bao.hua@hisilicon.com>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
"arnd@arndb.de" <arnd@arndb.de>,
"geert@linux-m68k.org" <geert@linux-m68k.org>,
"funaho@jurai.org" <funaho@jurai.org>,
"philb@gnu.org" <philb@gnu.org>,
"corbet@lwn.net" <corbet@lwn.net>,
"mingo@redhat.com" <mingo@redhat.com>,
"linux-m68k@lists.linux-m68k.org"
<linux-m68k@lists.linux-m68k.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [RFC] IRQ handlers run with some high-priority interrupts(not NMI) enabled on some platform
Date: Fri, 19 Feb 2021 11:11:20 +1300 [thread overview]
Message-ID: <a8595ec5-88db-072c-9cc3-7a3a301fe191@gmail.com> (raw)
In-Reply-To: <CAK8P3a0VquJPxvS8B=2kLQ5y=h5BftJDR7WJYmj3hgQ8yQY5=Q@mail.gmail.com>
On 19/02/21 12:19 am, Arnd Bergmann wrote:
> drivers/net/ethernet/8390/apne.c
> drivers/net/ethernet/8390/ax88796.c
> drivers/net/ethernet/8390/hydra.c
> drivers/net/ethernet/8390/mac8390.c
> drivers/net/ethernet/8390/ne.c
> drivers/net/ethernet/8390/zorro8390.c
[...]
> Most of these are normal short-lived interrupts that only transfer
> a few bytes or schedule deferred processing of some sort.
> Most of the scsi and network drivers process the data in
> a softirq, so those are generally fine here, but I do see that 8390
> (ne2000) ethernet and the drivers/ide drivers do transfer their
> data in hardirq context.
>
> Arnd
8390 ethernet drivers are widely used on m68k platforms (Amiga and
Atari). At least on Amiga, the corresponding interrupt is a hardirq so
I'd advise caution. That said, the 8390 drivers might benefit from some
refactoring (the way these drivers are compiled does prevent e.g. the
APNE driver from being used with two different variants of PCMCIA
interfaces. I had begun some work on making IO primitives runtime
selected two years ago but that ended up looking too ugly ...).
Can't recall what IPL the 8390 interrupts operate at - Geert?
Regarding allowing preemption of hardirqs - at least in 2017, that was
considered perfectly OK (see Linus' comment on
https://lore.kernel.org/patchwork/patch/794954/). I concur with Finn on
this one - we did look for potential issues with the way irqs_disabled()
is defined on m68k (for me, in the context of the above bug that caused
memory corruption on my system), and found none.
Cheers,
Michael
next prev parent reply other threads:[~2021-02-18 22:12 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-12 1:18 [RFC] IRQ handlers run with some high-priority interrupts(not NMI) enabled on some platform Song Bao Hua (Barry Song)
2021-02-12 22:34 ` Arnd Bergmann
2021-02-12 23:00 ` Song Bao Hua (Barry Song)
2021-02-12 23:05 ` Arnd Bergmann
2021-02-12 23:46 ` Song Bao Hua (Barry Song)
2021-02-13 16:32 ` Arnd Bergmann
2021-02-13 22:18 ` Song Bao Hua (Barry Song)
2021-02-13 23:18 ` Song Bao Hua (Barry Song)
2021-02-14 5:10 ` Finn Thain
2021-02-15 13:06 ` Andy Shevchenko
2021-02-15 22:22 ` Finn Thain
2021-02-17 22:41 ` Song Bao Hua (Barry Song)
2021-02-18 5:30 ` Finn Thain
2021-02-18 11:19 ` Arnd Bergmann
2021-02-18 12:30 ` Geert Uytterhoeven
2021-02-18 13:59 ` Arnd Bergmann
2021-02-18 15:38 ` Geert Uytterhoeven
2021-02-18 22:11 ` Michael Schmitz [this message]
2021-02-19 8:10 ` Geert Uytterhoeven
2021-02-19 22:30 ` Brad Boyer
2021-02-20 6:32 ` Finn Thain
2021-02-20 7:08 ` Brad Boyer
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