linux-kernel - Re: [BUG] Stuck key syndrome (was: Re: [PATCH net-next v2] net: dsa: microchip: Add SGMII port support to KSZ9477 switch)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aBuciGLIzokQrjrE@shell.armlinux.org.uk>
Date: Wed, 7 May 2025 18:46:48 +0100
From: "Russell King (Oracle)" <linux@...linux.org.uk>
To: Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>,
	Maxime Chevallier <maxime.chevallier@...tlin.com>,
	Andrew Lunn <andrew@...n.ch>,
	Woojung Huh <woojung.huh@...rochip.com>,
	Vladimir Oltean <olteanv@...il.com>,
	Heiner Kallweit <hkallweit1@...il.com>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [BUG] Stuck key syndrome (was: Re: [PATCH net-next v2] net: dsa:
 microchip: Add SGMII port support to KSZ9477 switch)

On Wed, May 07, 2025 at 10:23:37AM -0700, Dmitry Torokhov wrote:
> On Wed, May 07, 2025 at 07:46:03AM -0700, Linus Torvalds wrote:
> > On Wed, 7 May 2025 at 04:51, Maxime Chevallier
> > <maxime.chevallier@...tlin.com> wrote:
> > >
> > > So, same as you, it'll take a long time for me to say with some amount
> > > of certainty that 'i8042_unlock=1' has a beneficial effect, of
> > > course unless I see the problem happen again in the meantime.
> > 
> > Christ. You'd expect that any i8042 issues had been fixed long ago,
> > but the problem is that the chip doesn't necessarily even exist in
> > modern platforms, and everybody just fakes it.
> 
> It has not existed as a real chip for more than 20 years I believe. It's
> all faked in firmware and embedded controllers that fake it in their
> firmwares.
> 
> And newer firmware tend to implement less and less of it, just what OS
> that devices that ship with it needs.
> 
> > 
> > So the platform presumably still has hardware support for it, but it's
> > mostly in the form of "take a trap when accessing the legacy keyboard
> > ports, and fake it in firmware".
> > 
> > Although it doesn't help that there are literally decades of clone
> > chips and hacky real hardware that extended on the i8042 in various
> > more-or-less compatible ways.
> > 
> > Which makes all of these things almost entirely undebuggable.
> > 
> > I'm surprised the XPS9510 would be particularly troublesome - I've had
> > an XPS for years (older version, obviously) with no issues outside of
> > WiFi sometimes acting up. But random firmware...
> > 
> > I doubt it's "keylock active", but who knows. I get that on my xps
> > too, it's a random bit that doesn't really mean much. But - because of
> > all the reasons above - who knows...
> 
> It is typically harmless and whats more trying to "unlock" 8042 when it
> reports being locked might confuse 8042 emulation.

So I think the summary of this thread is... laptop keyboards are
unreliable, and it's a lottery whether any particular laptop works
or remains working over firmware updates.

Surely that essentially means, laptops are basically unreliable
devices?

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!