Messages in this thread | | | Date | Wed, 5 Dec 2018 20:20:36 +0100 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH v2 BlueZ] hid2hci: Fix udev rules for linux-4.14+ |
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On Wed, Dec 05, 2018 at 05:40:32PM +0200, Ville Syrjälä wrote: > On Wed, Dec 05, 2018 at 08:06:21AM +0100, Greg Kroah-Hartman wrote: > > On Tue, Dec 04, 2018 at 10:41:17PM +0200, Ville Syrjala wrote: > > > From: Ville Syrjälä <ville.syrjala@linux.intel.com> > > > > > > Since commit 1455cf8dbfd0 ("driver core: emit uevents when > > > device is bound to a driver") the kernel started emitting > > > "bind" and "unbind" uevents which confuse the hid2hci > > > udev rules. > > > > > > The symptoms on an affected machine (Dell E5400 in my case) > > > include bluetooth devices not appearing and udev hogging > > > the cpu as it's busy processing a constant stream of these > > > "bind"+"unbind" uevents. > > > > What is causing a "stream" of bind and unbind events? This only happens > > when a device is attached to a driver or removed from a driver, which is > > caused by something else happening. > > Not sure if it's just due to this thing causing devices to > appear/disappear during bind/unbind events or what.
Someone has to be telling the kernel to bind/unbind from a driver to a device, it doesn't do it on its own. Look at your other rules/scripts for that.
Also note that the kernel has been doing this for over a year now (since 4.l4), what just happened in 4.19 to cause this to be an issue?
> > This should not be a normal > > occurance, unless something odd is happening to your hardware? > > It's not specific to my hardware. Lot's of people are affected. > See eg. > https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1759836 > > Acutally looking through that bug it seems someone else noticed > hid2hci failing lot in the logs. So maybe it's just that we already > switched the mode during "add", and then we try to redo the same > thing during "bind" which fails, and that then causes and unbind?
You have to manually unbind the device, the kernel does not do that. So perhaps you have a broken udev rule somewhere else that would do something odd like unbind/bind?
I don't see this happening on my systems, but hey, I know better than to run Ubuntu :)
thanks,
greg k-h
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