cdc-wdm.c broke Synopsis USB HC

[Markus Gothe]

Turned out that start submitting the validity urn when the driver is loaded (inspired by usbnet.c status-check),
instead of enabling / disabling periodics and the URB upon open/release saved the controller from halting.

:-)

//M

On 16 Jun 2014, at 22:32 , Markus Gothe <nietzsche at lysator.liu.se> wrote:

> Hmm… I was thinking the HC could make this decision since it claims an IRQ.
> 
> Then how the driver should behave is another question. However the cdc-wdm approach seems to be kinda no-go on these controllers.
> I succesfully patched the ECHI scheduler but then broken other functionality on a "hindenbug basis”. :-/ So I’ll better rewrite the validity URB int-callback.
> 
> And yes I guess you are correct, there should be a thread, task let or bottomhalf to poll the data IMO.
> 
> //M
> 
> On 16 Jun 2014, at 21:52 , Bjørn Mork <bjorn at mork.no> wrote:
> 
>> Markus Gothe <nietzsche at lysator.liu.se> writes:
>> 
>>> I think it is time for a redesign of the WDM driver. I havent read the
>>> specs but in short it will cause timing issues with some SoC-hubs from
>>> Synopsis. GobiNet also invokes the error halting the hub. Basically
>>> both drivers shares a polling-routine based on sending the same
>>> interrupt URB over and over again, hence creating a polling loop.
>> 
>> That's the way USB works...  The host polls.  If it doesn't then the
>> device cannot send anything.
>> 
>>> For periodic transfers this seem to halt the Synopsis hub FUBAR. So is
>>> there any pointers in the WMC documentation on how to let the
>>> piggy-backing device create "real" IRQs when there is data to read?
>> 
>> A USB device cannot create "real" IRQs.
>> 
>> 
>> 
>> Bjørn
> 
> 
> 
> //Markus - The panama-hat hacker
> 
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//Markus - The panama-hat hacker

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