From: Paul Menzel <firstname.lastname@example.org>
To: Dmitry Torokhov <email@example.com>
Cc: firstname.lastname@example.org, Dell.Client.Kernel@dell.com,
Benjamin Tissoires <email@example.com>
Subject: Re: Dell XPS 13 9310 2-in-1: psmouse serio1: synaptics: Unable to query device: -5
Date: Tue, 16 Aug 2022 07:00:55 +0200 [thread overview]
Message-ID: <firstname.lastname@example.org> (raw)
[Resend without attachment as linux-input@ bounced it due to exceeding
the size limit.]
[Cc: -Mario as he works at AMD now.; +Dell.Client.Kernel@dell.com, but I
never received a response from them.; +Benjamin]
Am 07.12.20 um 22:09 schrieb Limonciello, Mario:
>>> The messages you're seeing are harmless in this laptop.
>>> The laptop input is supported using the hid-multitouch and i2c-hid drivers as
>>> noted in your messages.
>>> [ 393.280115] input: DLL09FF:01 06CB:CE39 Touchpad as /devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-2/i2c- DLL09FF:01/0018:06CB:CE39.0002/input/input21
>>> [ 393.280221] hid-multitouch 0018:06CB:CE39.0002: input,hidraw1: I2C HID v1.00 Mouse [DLL09FF:01 06CB:CE39] on i2c-DLL09FF:01
>> Where is
>> input: PS/2 Synaptics TouchPad as /devices/platform/i8042/serio1/input/input2
>> coming from then, and what touchpad is that supposed to be?
>> If it’s harmless, should the log level be decreased from error to debug?
> There are two common scenarios that happen on Dell's laptops.
> 1) Touchpads are connected to 2 buses. Such as PS2 and i2c.
> 2) Touchpads are connected only to 1 bus, but the EC can emulate
> a PS/2 touchpad in the PS/2 bus until OS drivers have started up.
> This allows using it in BIOS setup for example without an UEFI DXE
> driver for I2C. It's not generally safe for using it this way in
> a general purpose operating system.
> I don't have the schematics for the model you referred to confirm it,
> but I suspect it's likely the second case. In the first case you should
> see some sort of message along the lines that the touchpad supports
> another bus, you should make sure you have those drivers enabled.
> The key however is that the PS/2 driver and i2c-hid drivers don't have
> any handshake here whatsoever about what happened. This has come
> up several times over the years, but because there is "no negative
> impact" to a ghost touchpad device there has been no effort by
> anyone to fix it. You can compile your kernel without psmouse and it
> should then not be present.
> In systems with the first scenario pretty much when the I2C driver
> starts up, the PS/2 mode is turned off and you won't get traffic on
> the bus. Because of kernel probing order you would end up with psmouse
> mentioning it's supported by another bus probably, and then later in
> startup the i2c one starts up. The I2C driver can't just notify psmouse
> it's supporting something because it can't prove the device it supports
> now is the same one that was supported by psmouse.
> In the second scenario you're talking about a virtual device from the EC
> and a real device on the I2C bus. So the notification flow is even more
> Here's my two low effort ideas:
> 1) Adjust this so when kernel is compiled with the support for both can we
> make psmouse wait to initialize until after i2c-hid and hid-multitouch
> have finished? This is probably a question for Benjamin if that would
> actually work and it's as low effort as I think it would be.
> 2) Downgrade all psmouse messaging to debug. Realistically modern
> machines are no longer using psmouse in the first place. The messaging
> benefits no one except those that have a problem with older hardware,
> which can then be told to boot with dyndebug turned on for psmouse.
Today I have seen this also on a Dell XPS 13 9370 (system firmware
1.15.0, 06/07/2021) with Linux 5.18.16. The message is logged on the
screen even with `quiet` passed – as it’s log level error, and the user
sees it when entering the LUKS passphrase.
Which one of Mario’s suggestions do the developers prefer?
prev parent reply other threads:[~2022-08-16 7:52 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <email@example.com>
2020-12-07 17:40 ` Dell XPS 13 9310 2-in-1: psmouse serio1: synaptics: Unable to query device: -5 Limonciello, Mario
2020-12-07 20:52 ` Paul Menzel
2020-12-07 21:09 ` Limonciello, Mario
2022-08-16 5:00 ` Paul Menzel [this message]
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