[pvrusb2] [PATCH] pvrusb2: Fix oops on tear-down when radio support is not present

[Mike Isely]

Thanks.  I'll get that patch pushed upstream.

The soft lockup situation I have not seen yet.  That isn't to say it 
isn't happening, but rather that I will probably need a lot of info in 
order to reproduce it here.  (This sort of problem can be a real devil 
to reproduce especially on non-identical equipment.)

  -Mike

On Sun, 27 Oct 2019, Diego Rivera wrote:

> So here's another tidbit that we may eventually want to look into: under unknown circumstances,
> during driver bootup, a soft lockup will take place which renders the machine inoperable. This also
> happens in the VM. I'll try to fish out logs to see if anything stands out.
> That said, the driver patch does indeed seem to take care of the death due to unplug/replug.  Now I
> have to test thoroughly to see if a soft-reset results in the device coming back to life after a
> hang. This is great progress, though!
> I'll keep you posted with everything I find during these next few days. For now, I'd submit the
> patch regardless since it's an improvement nonetheless.
> Cheers! And thanks again!
> 
> On Sun, 2019-10-27 at 18:15 -0600, Diego Rivera wrote:
> > Ok so excellent news! I can now remove and re-attach the devices with no oopses!!  I'm testing the
> > "soft-reset" part now to see if that'll work as well, but I now have a workaround for that, too!!
> > I didn't see too much noise on the logs from the sysfs teardown, then again I didn't look too
> > hard.  What I meant by "parameter" was just that: a runtime flag that could be turned on/off by a
> > user if they grow tired of the noise on the logs.  For the I2C thing, I think blacklisting the
> > I2C-IR driver like we had done before should be enough of a workaround for now.
> > Thanks for this!!
> > Cheers!
> > -- 
> > 
> > 
> > 
> > Diego Rivera
> > 
> > On Sun, 2019-10-27 at 18:19 -0500, Mike Isely wrote:
> > > The sysfs teardown issue right now is largely cosmetic - you just get log noise but the end
> > > result appears to still be correct.  Obviously this still needs to be fixed, because getting
> > > stack traces in the kernel message log generally sucks.
> > > There actually is a pvrusb2 kernel config parameter you can set at compile time which will
> > > disable the sysfs piece of this.  (Not a run-time switch though.)
> > >   -Mike
> > > On Sun, 27 Oct 2019, Diego Rivera wrote:
> > > > I had a thought about the sysfs teardown race you mentioned. Would it causetoo many problems
> > > > if instead you added a module parameter to selectivelydisable that bit and let the rest of the
> > > > kernel do the teardown instead?
> > > > That might be enough of an optional workaround for now, since that doesindeed seem like a
> > > > bigger challenge...unless, of course, that approachbrings more problems into focus...
> > > > Just a thought...
> > > > Cheers!
> > > > --
> > > > Diego Rivera
> 

-- 

Mike Isely
isely @ isely (dot) net
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