Coldpluging or USB Issues ?

From: Razvan Gavril
Date: Thu May 11 2006 - 04:24:24 EST


For start, i don't know if a big part of the problem is not cause by userland tools and not the kernel itself, but i think is proper to ask this questions here as there are a lot of people who can guide me to the right place to search for information.

We are developing a custom debian sarge based linux distribution focused on home entertainment & other. Since we made the switch from 2.6.13 to 2.6.15 we come to a lot of problems cause by coldpluging, sometimes the module for various usb devices are not loaded at boot (by the hotplug scripts). Since the hotplug script that we use with 2.6.15 are the same with the one that we've been using with 2.6.13 i suspect that something in the kernel changed because they used to work flawless with the older version. For the last week we updated to 2.6.16.12 hoping that it fixes this issue but nothing has changed, the problem is still there, we even had bigger problem, not directly related to coldplug, when a computer had multiple usb devices attached it worked for a while that all the usb system stoped working, when rebooting , it even blocked when loading the modules for usb, we needed to remove some of the usb devices to get it boot again.

We tried switching from the debian default bash hotplug scripts and use a alternative version written in perl but the problem are still there so the idea that this has something to do with the kernel is getting closer to reality.

As far as i know since 2.6.15 there is a new coldplug mechanism using uevent and switching to a newer version of udevd that can do the cold plugging and replacing the old hotplug scripts would be the natural next step but before doing this i need to ask some questions like :
1) Where there any changes sine 2.6.15 that could cause the old hotplug scripts to work reliable because most part of the time (95%) they are working ?
2) Upgrading to newer version of udevd to let the udev scripts to do the coldpluging can solve any issues that where described ?

If any of you wants to debug the problems fill free to contact me as i can provide you with all the needed information.

Thx
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/