cdc-wdm.c broke Synopsis USB HC

[Markus Gothe]

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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