Re: USB transaction errors causing RCU stalls and kernel panics

[Oliver Neukum <oneukum@suse.com>]

Am Mittwoch, den 11.03.2020, 14:59 +0000 schrieb Jonas Karlsson:
> Hi Oliver,
> 
> > Hi,
> > 
> > it is good that we have something that works.
> > It would be even better if we understood exactly how it works. In fact that
> > these patches work and are needed may very well indicate that error
> > handling on at least some XHCs does not work as expected.
> > 
> > So a question and a request, if I may.
> > Did you run the test with autosuspend disabled? If so could you retest with it
> > enabled?
> 
> I have only tested with autosuspend enabled.
> 
> > Secondly could you run tests with
> > 
> > commit 7c8f7af078a4eda73f347667d12584736e613062
> > Author: Oliver Neukum <oneukum@suse.com>
> > Date:   Thu Mar 5 11:16:02 2020 +0100
> > 
> >     cdc-acm: close race betrween suspend() and acm_softint
> > 
> > not applied (respectively reverted) with and without autosuspend?
> 
> I ran a test with this commit reverted and saw no difference in behavior.
> i.e we do not get event spam with this commit reverted.
> I tested with enabled and disabled autosuspend.
> 
> > 
> > 	Regards
> > 		Oliver
> > 
> > PS: When I submit upstream, may I add your 'Tested-by'?
> 
> Sure, you can add me, but I have only tested that this specific problem
> seems to be solved. The normal functionality has not been tested  properly yet
> on our side. 

Hi,

thank you. In this case it looks like the wisest course is to wait
a few days then. Thank you for thorough testing.

	Regards
		Oliver