[Gta04-owner] Modem reenummerating

EdorFaus edorfaus at xepher.net
Mon Aug 26 23:16:42 CEST 2013

On 08/26/2013 12:47 PM, Radek Polak wrote:
> On Sunday, August 25, 2013 01:22:00 PM Christ van Willegen wrote:
>  > On Sat, Aug 24, 2013 at 11:24 PM, Lukas Märdian <luk at slyon.de> wrote:
>  > > Am 24.08.2013 23:04, schrieb NeilBrown:
>  > >> I'm starting to think the the re-enumeration could be an omap-usb
>  > >> problem. I turned off a couple of power-saving features and the rate
>  > >> at which my modem reenumerates went way down. Sometimes the the modem
>  > >
>  > > Hmm could this by any chance have something to do with the infamous
>  > > Linux-USB problem, recently pointed out by Sarah Sharp?
>  > >
>  > > http://permalink.gmane.org/gmane.linux.usb.general/93288
>  >
>  > Well, it's worth a try!

> I just tried the patch and it does not help with our problem :(

Hm, maybe try an even longer delay? The 20ms was based on tests with a 
specific Intel chip, so maybe ours is even slower?

I guess one way to test that theory would be to set the delay very long, 
like a whole second or so - something that might not be usable in 
practice, but at least should be definitely long enough if that *is* the 

> Btw the reenumaration happens even without suspend/resume at all.

Oh, hm. That indeed suggests deeper issues.

Or... at least *other* issues - which might possibly be additional 
instead of alternative? *shrug*

Hey, there's an idea... I don't know if the external USB port is 
connected in an equivalent way as the modem is (or if there's any other 
internal USB devices we could use), but if that port is set to host mode 
and a device is connected, is that device also reenumerated when the 
modem is?
If it is, it's unlikely to be a problem with the modem. If not, we could 
try to figure out what the difference between them is?

Of course, if it *is* a timing problem, that test might not yield any 
useful info, since that other device would have different timing, 
perhaps enough so to never trigger reenumeration anyway...


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