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wcerfgba

Member

Registered: 2016-01-30

Posts: 3

[SOLVED] Confused about kernel history

Hi all,

In an effort to get my ALPS touchpad detected correctly, I started looking in to `drivers/input/mouse/alps.c` in the Linux kernel.

I am running kernel version 4.9.8-1-ARCH:

[john@slate linux]$ uname -a
Linux slate 4.9.8-1-ARCH #1 SMP PREEMPT Mon Feb 6 12:59:40 CET 2017 x86_64 GNU/Linux

Looking in dmesg, I can see the kernel reporting that my touchpad is not detected as ALPS:

[john@slate linux]$ dmesg | grep ALPS
[    3.094688] psmouse serio1: alps: Unknown ALPS touchpad: E7=73 03 28, EC=73 01 13

However, this message was changed in v3.16-rc6 back in 2014-08-26, as shown by this commit in linux-stable: https://git.kernel.org/cgit/linux/kerne … b498afb93b:

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index a59a1a6..a956b98 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -2234,8 +2234,8 @@ static int alps_identify(struct psmouse *psmouse, struct alps_data *priv)
 		return 0;
 	}
 
-	psmouse_info(psmouse,
-		     "Unknown ALPS touchpad: E7=%3ph, EC=%3ph\n", e7, ec);
+	psmouse_dbg(psmouse,
+		    "Likely not an ALPS touchpad: E7=%3ph, EC=%3ph\n", e7, ec);
 
 	return -EINVAL;
 }

I find it very surprising that my kernel is reporting a message from such an old version. Indeed, I have confirmed that the message should be "Likely not an ALPS touchpad" (as opposed to "Unknown ALPS touchpad") in 4.9, as shown in the tree here: https://git.kernel.org/cgit/linux/kerne … .9.y#n2836:

} else {
			psmouse_dbg(psmouse,
				    "Likely not an ALPS touchpad: E7=%3ph, EC=%3ph\n", e7, ec);
			return -EINVAL;
		}

I have confirmed that there are no DKMS modules which could be overriding this and taking me back to an earlier version of the psmouse driver. I have also downloaded the kernel source referenced in the kernel PKGBUILD here: https://git.archlinux.org/svntogit/pack … ages/linux and the new message is present there also.

Can someone please enlighten me as to why my psmouse driver seems to be two and a half years old?

Last edited by wcerfgba (2017-02-20 19:11:08)

Lone_Wolf

Forum Moderator

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 11,922

Re: [SOLVED] Confused about kernel history

dmesg | grep ALPS
[    3.094688] psmouse serio1: alps: Unknown ALPS touchpad: E7=73 03 28, EC=73 01 13

maybe serio1 designates a different type of psmouse that is not handled by drivers/input/mouse/alps.c ?

A search for "Unknown ALPS touchpad" in the kernel source should clarify that.

The dmesg you posted suggests your

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seth

Member

Registered: 2012-09-03

Posts: 51,224

Re: [SOLVED] Confused about kernel history

check "modinfo psmouse"
I checked /lib/modules/4.9.8-1-ARCH/kernel/drivers/input/mouse/psmouse.ko.gz (copy, gunzip, strings | grep) and it has the "alps: Likely not an ALPS touchpad" string (only)

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wcerfgba

Member

Registered: 2016-01-30

Posts: 3

Re: [SOLVED] Confused about kernel history

Thanks both for your help.

I upgraded my kernel last night before powering down and today it seems that the problem has been resolved: my mouse is detected correctly and the correct module has been loaded. Not sure what the original problem was though.

Marking as solved.