[pvrusb2] Ability to fully reset a PVRUSB2 Device

isely at isely.net isely at isely.net
Sat Mar 16 18:16:00 CDT 2019 

I'd say there's a very good chance of fixing this.  The critical issue 
for me is getting the time to dig into it.  I've been out of this so 
long that my test setup is boxed up somewhere...

Once I reproduce the problem I think it's pretty likely I can find a 
fix.  Odds are that some aspects of the USB stack's interface to client 
drivers has changed in a manner that breaks use of it by the pvrusb2 
driver.  It's just a matter of figuring that out and dealing with it.  
Maybe a disconnect callback happening in a way now that the driver 
doesn't expect.  With this many years since the last substantial change, 
this is certainly possible.

  -Mike


On Sat, 16 Mar 2019, Diego Rivera wrote:

> I'd offer to help fix this but I'm not knowledgeable enough in building usb
> kernel drivers to be of much use...
> 
> But any help I can offer is definitely at your disposal.
> 
> Do you think there's any chance of fixing this?
> 
> --
> 
> Diego Rivera
> 
> On Sat, Mar 16, 2019, 17:08 <isely at isely.net> wrote:
> 
> >
> > Based on other messages here (which I just now saw), it looks like
> > there's been a USB stack change in the kernel (for who knows how long
> > ago) that prevent hot-unplug from working.  That is supposed to work.
> > It used to.  Oh joy.
> >
> >   -Mike
> >
> >
> > On Sat, 16 Mar 2019, Diego Rivera wrote:
> >
> > > My bigger concern is why the driver is refusing to give up on "bad"
> > > devices...
> > >
> > > Also I found a solution for keeping the digital side out of TVH: change
> > the
> > > Unix group for dvb devices via udev :)
> > >
> > > I might come up with a more detailed rule only for the 1950s, but for now
> > > that'll do!
> > >
> > > Cheers!
> > >
> > > --
> > >
> > > Diego Rivera
> > >
> > > On Sat, Mar 16, 2019, 16:27 <isely at isely.net> wrote:
> > >
> > > >
> > > > Short of preventing the digital stuff from being available in the
> > > > kernel, no.  The driver is set up to always exploit whatever it can...
> > > >
> > > > Catching up on the other replies...
> > > >
> > > >
> > > > On Sat, 16 Mar 2019, Diego Rivera wrote:
> > > >
> > > > > Negative on that count either... I unplugged the device and a few
> > > > minutes later it's still spewing
> > > > > out that message.
> > > > > Side question: is there any way to disable the digital side of the
> > > > driver upon launch? Maybe a
> > > > > parameter that can be passed in?
> > > > > Thanks for responding, too!! I realize this is a stale device but I
> > > > certainly appreciate your time!
> > > > > On Sat, 2019-03-16 at 11:36 -0500, isely at isely.net wrote:
> > > > > > OK, now unplug it if you haven't already done so.  That should
> > break
> > > > the connection between the
> > > > > > driver and the hardware and cause the pvrusb2 driver to eventually
> > > > stop crabbing and let
> > > > > > go.  That's a scenario that I executed A LOT when debugging the
> > > > driver...
> > > > > > (If that doesn't work then there may be another problem.)
> > > > > >   -Mike
> > > > > >
> > > > > > On Sat, 16 Mar 2019, Diego Rivera wrote:
> > > > > > "On the digital side"... you're right! Turns out TVHeadend was
> > > > grabbing the digital side of
> > > > > > thetuners - I'll have to figure out a way to disable that, since I
> > > > don't need that.  That said,
> > > > > > once Iturned off TVHeadend, modprobe -r no longer complained about
> > the
> > > > module being in
> > > > > > use.However, it just hung .... and the log is littered with
> > "pvrusb2:
> > > > Attempted to execute
> > > > > > controltransfer when device not ok"So definitely something's wrong
> > > > here because either the module
> > > > > > is definitely caring what happens tothe device(s), or something in
> > the
> > > > overarching kernel
> > > > > > framework changed that appears to need updateson the module in
> > order
> > > > to properly comply... maybe
> > > > > > USB events were removed/modified that the driverexpects for correct
> > > > functioning?Just shooting
> > > > > > blanks here... if there's additional debug information that I can
> > > > provide, I'll bemore than happy
> > > > > > to try to rustle that up for you!Cheers!
> > > > > > On Sat, 2019-03-16 at 11:26 -0500, isely at isely.net wrote:
> > > > > > Interesting.The kernel of course will refuse to a remove a module
> > > > until all references to it go
> > > > > > away.The USB side of the pvrus2 driver won't (shouldn't) care so
> > > > physically unplugged the USB
> > > > > > cable(and doing all manner of USB reset attempts) isn't going to
> > help
> > > > (or hurt - the driver
> > > > > > won'tcare).The problem is not that the driver is referencing the
> > USB
> > > > port but rather that other
> > > > > > entities arereferencing the driver.  So the first obvious case is
> > to
> > > > ensure nobody has it open
> > > > > > which youdid.  Another thing to look at is to see what if other
> > kernel
> > > > modules are referencing
> > > > > > thedriver.  This might be happening on the digital side.  If you
> > run
> > > > lsmod to get a list of
> > > > > > kernelmodules installed you should also see reference counts and a
> > > > list of what other kernel
> > > > > > modules arecausing that count to be non-zero.  If there are other
> > > > modules listed, then they need
> > > > > > to beremoved first - lowering the reference count - before you can
> > > > remove the pvrusb2 driver.Yes,
> > > > > > it's been a long time since I've messed with this driver, sadly,
> > but
> > > > my recollection is
> > > > > > thatbasically while the pvrusb2 module will reference a lot of
> > other
> > > > modules to get its job done,
> > > > > > Ididn't think there was any kernel modules that could reference the
> > > > pvrusb2 driver.  When
> > > > > > thepvrusb2 driver is installed into the running kernel, it will tie
> > > > itself to the other modules
> > > > > > thatis needs, but when you modprobe -r pvrusb2, it SHOULD undo all
> > > > that.  It's conceivable that
> > > > > > thesurrounding kernel environment has changed in ways that
> > invalidate
> > > > this - though I think if
> > > > > > thatwere the case I'd see a lot of screaming here :-)  (Either
> > that or
> > > > almost nobody is using
> > > > > > thisanymore...)  -Mike
> > > > > > On Fri, 15 Mar 2019, Diego Rivera wrote:Hi!I realize it's been MANY
> > > > years since you've messed with
> > > > > > this driver, but I figured why not ask?Ifthere's a better
> > place/person
> > > > to send this to, please let
> > > > > > me know and I'll be glad to go knockonthat door instead!Here goes:
> > I
> > > > have a system with two WinTV-
> > > > > > HVR-1950 devices (long story, still use analog cablehere)which I've
> > > > managed to get working with
> > > > > > TVHeadend to supply Analog TV support via thedigitalplatform (yay,
> > me!
> > > > ☺).However, I'm running
> > > > > > into a problem due likely to the age of one of the devices
> > > > (probablystartingto get wonky).  Every
> > > > > > so often one of the devices ceases to function and just "dies".
> > > > Itneeds tobe physically
> > > > > > disconnected (or the machine rebooted) to get back to working
> > order.
> > > > I'vetried manyapproaches to
> > > > > > reset the USB bus or the device itself via software but none of
> > them
> > > > seemto work:* If I try
> > > > > > "modprobe -r pvrusb2" I get the error that the module is in use
> > (but I
> > > > have nouserprocesses
> > > > > > actively using any of the pvrusb2 devices! I've made sure!).* If I
> > try
> > > > to issueUSBDEVFS_DISCONNECT
> > > > > > or USBDEVFS_RESET commands via IOCTL, neither works and areboot is
> > > > nowrequired.* If I try to reset
> > > > > > the whole USB bus via /sys/bus/pci/drivers/?hci_hcd/unbind and
> > bind,it
> > > > doesn'twork and a reboot is
> > > > > > now required* If I try to use
> > /sys/bus/usb/drivers/pvrusb2/unbindand
> > > > bind, it does'nt work and a
> > > > > > reboot is nowrequiredIn the last 3 cases, syslog ends up littered
> > with
> > > > the message "pvrusb2:
> > > > > > Attempted to executecontroltransfer when device not ok", output
> > > > continually regardless of any
> > > > > > attempt to rebind.  Thissuggeststhat once the device is "not ok"
> > > > (dead?), the driver doesn't
> > > > > > attempt to clean it up(should it?)Is there any other way to force a
> > > > full reset and
> > > > > > reinitialization of a pvrusb2 device viasoftwarewithout actually
> > > > having to disconnect/reconnect
> > > > > > the device or reboot the machine?Thanks!
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > >
> > > >
> > > > --
> > > >
> > > > Mike Isely
> > > > isely @ isely (dot) net
> > > > PGP: 03 54 43 4D 75 E5 CC 92 71 16 01 E2 B5 F5 C1 E8
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> >
> > --
> >
> > Mike Isely
> > isely @ isely (dot) net
> > PGP: 03 54 43 4D 75 E5 CC 92 71 16 01 E2 B5 F5 C1 E8
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-- 

Mike Isely
isely @ isely (dot) net
PGP: 03 54 43 4D 75 E5 CC 92 71 16 01 E2 B5 F5 C1 E8

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