Order of loading modules

Order of loading modules

[thobi]

I got a digitizer that run well with linux. Then I decided to compile
the
USB drivers as modules, and I got only strange movements on the screen. 
Also it seemed that the button is being already pressed. So I
investigated
what had changed and found out, that if I load the modules by hand the 
digitizer is again working well.  The reason was, that by using the 
hotplug scripts the usbmouse module was loaded before the hid one.
After changing usb.agent ...
-       DRIVERS="$module $DRIVERS"
+       DRIVERS="$DRIVERS $module"
... everything was fine again.
I think a generic solution has to be found about maintaining a certain
order
when loading the modules.

   Tobias

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Re: Order of loading modules

[David Brownell]

[-- Attachment #1: Type: text/plain, Size: 1623 bytes --]

Sounds like a bug in how the hid code hooks up to the
input subsystem ... dependency order is supposed to be
sufficient to ensure correct module initialization, anything
else seems completly impractical to me.

FYI if you've been using the 2.4.5-ac series, with the
modified hid core (for better UPS support), you may
want a hotplug-related patch I just posted to the USB
list (attached).  Without that patch, the hid driver will
try to attach itself to _every_ USB device.

- Dave

----- Original Message ----- 
From: "thobi" <Tobias.Hoffmann@fen-net.de>
To: <linux-hotplug-devel@lists.sourceforge.net>
Sent: Wednesday, June 13, 2001 7:49 AM
Subject: Order of loading modules


> I got a digitizer that run well with linux. Then I decided to compile
> the
> USB drivers as modules, and I got only strange movements on the screen. 
> Also it seemed that the button is being already pressed. So I
> investigated
> what had changed and found out, that if I load the modules by hand the 
> digitizer is again working well.  The reason was, that by using the 
> hotplug scripts the usbmouse module was loaded before the hid one.
> After changing usb.agent ...
> -       DRIVERS="$module $DRIVERS"
> +       DRIVERS="$DRIVERS $module"
> ... everything was fine again.
> I think a generic solution has to be found about maintaining a certain
> order
> when loading the modules.
> 
>    Tobias
> 
> _______________________________________________
> Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
> Linux-hotplug-devel@lists.sourceforge.net
> http://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

[-- Attachment #2: hid-0613.patch --]
[-- Type: application/octet-stream, Size: 404 bytes --]

--- linux/drivers/usb-ac6/hid-core.c	Tue Jun 12 20:12:20 2001
+++ linux/drivers/usb/hid-core.c	Wed Jun 13 07:37:43 2001
@@ -1264,7 +1264,10 @@
 }
 
 static struct usb_device_id hid_usb_ids [] = {
-	{ bInterfaceClass: USB_INTERFACE_CLASS_HID},
+	{
+	    match_flags:	USB_DEVICE_ID_MATCH_INT_CLASS,
+	    bInterfaceClass:	USB_INTERFACE_CLASS_HID
+	},
 	{ }						/* Terminating entry */
 };