netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Andrew Lunn <andrew@lunn.ch>
To: John David Anglin <dave.anglin@bell.net>
Cc: Russell King <linux@arm.linux.org.uk>,
	Vivien Didelot <vivien.didelot@savoirfairelinux.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	netdev@vger.kernel.org
Subject: Re: [PATCH v2] net: dsa: mv88e6xxx: Revise irq setup ordering
Date: Tue, 5 Feb 2019 03:21:49 +0100	[thread overview]
Message-ID: <20190205022149.GA10838@lunn.ch> (raw)
In-Reply-To: <8d8123cc-60f0-e236-e496-0aacf735fceb@bell.net>

> The problem is INTn can go low before the interrupt handler for it is
> registered and enabled.

> This can't happen.  The domain is setup immediately after registering
> the GPIO interrupt.
> The interrupt can't fire until one of the enables is set.

These two statement seem to contradict each other?

> These are set
> by mv88e6xxx_g2_irq_setup(),
> mv88e6xxx_g1_atu_prob_irq_setup() and
> mv88e6xxx_g1_vtu_prob_irq_setup().  These irqs
> are setup after mv88e6xxx_g1_irq_setup()/mv88e6xxx_irq_poll_setup() is
> called.  Thus, the
> irq domain is setup before the GPIO interrupt can fire.

At what point is INTn going low, causing you all these problems? I've
yet to see a real description of the race. Please give us a blow by
blow of how the race happens. And then explain how your fix actually
fixes this.

Also, i'm not yet convinced this hardware can actually work correctly
with edge interrupts. You can probably reduce the size of the race
window, but i don't think you can eliminate it. And if you cannot
eliminate it, at some point it is going to hit you.

     Andrew

  reply	other threads:[~2019-02-05  2:22 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-22 19:16 net: phylink: dsa: mv88e6xxx: flaky link detection on switch ports with internal PHYs John David Anglin
2019-01-22 20:28 ` Andrew Lunn
2019-01-22 21:40   ` John David Anglin
2019-01-22 22:36     ` Andrew Lunn
2019-01-22 23:52       ` John David Anglin
2019-01-23  0:11       ` John David Anglin
2019-01-23  0:22         ` Andrew Lunn
2019-01-25 16:30           ` John David Anglin
2019-01-25 16:48             ` Russell King - ARM Linux admin
2019-01-25 18:38               ` John David Anglin
2019-01-30 17:08           ` John David Anglin
2019-01-30 17:28             ` Andrew Lunn
2019-01-30 19:01               ` John David Anglin
2019-01-30 19:09                 ` Andrew Lunn
2019-01-30 22:24               ` John David Anglin
2019-01-30 22:38                 ` Andrew Lunn
2019-01-31  1:27                   ` John David Anglin
2019-01-31 17:27                     ` John David Anglin
2019-02-04 18:37                       ` [PATCH] net: phylink: dsa: mv88e6xxx: Revise irq setup ordering John David Anglin
2019-02-04 19:35                         ` Andrew Lunn
2019-02-04 19:52                           ` John David Anglin
2019-02-04 20:19                             ` Andrew Lunn
2019-02-04 21:38                               ` John David Anglin
2019-02-04 22:47                                 ` Andrew Lunn
2019-02-04 21:59                         ` [PATCH v2] net: " John David Anglin
2019-02-04 23:14                           ` Andrew Lunn
2019-02-05  0:38                             ` John David Anglin
2019-02-05  2:21                               ` Andrew Lunn [this message]
2019-02-05 19:20                                 ` John David Anglin
2019-02-05 19:54                                   ` Andrew Lunn
2019-02-05 18:37                           ` David Miller
2019-02-11 18:40                           ` [PATCH net] dsa: mv88e6xxx: Ensure all pending interrupts are handled prior to exit John David Anglin
2019-02-11 23:33                             ` Andrew Lunn
2019-02-12  0:57                               ` John David Anglin
2019-02-12  1:21                                 ` Andrew Lunn
2019-02-12  3:58                                 ` Andrew Lunn
2019-02-12  6:51                                   ` Heiner Kallweit
2019-02-12 12:56                                     ` Andrew Lunn
2019-02-12 18:42                                       ` Heiner Kallweit
2019-02-12 20:09                                       ` John David Anglin
2019-02-12 16:30                                     ` Russell King - ARM Linux admin
2019-02-12 20:11                                       ` Heiner Kallweit
2019-02-12 20:54                                       ` Heiner Kallweit
2019-02-12 22:55                                         ` Russell King - ARM Linux admin
2019-02-14  2:07                             ` Andrew Lunn
2019-02-14  4:47                               ` David Miller
2019-02-14  4:50                                 ` Andrew Lunn
2019-02-14 15:27                                   ` David Miller
2019-01-22 23:12 ` net: phylink: dsa: mv88e6xxx: flaky link detection on switch ports with internal PHYs Andrew Lunn
2019-01-22 23:48   ` John David Anglin
2019-01-23  0:00   ` John David Anglin
2019-01-23  0:04     ` Florian Fainelli

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190205022149.GA10838@lunn.ch \
    --to=andrew@lunn.ch \
    --cc=dave.anglin@bell.net \
    --cc=f.fainelli@gmail.com \
    --cc=linux@arm.linux.org.uk \
    --cc=netdev@vger.kernel.org \
    --cc=vivien.didelot@savoirfairelinux.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).