[RFC] [PATCH] usbatm.[ch]: multiple changes

Roman Kagan rkagan at mail.ru
Sat Apr 2 16:07:05 EST 2005

On Fri, Apr 01, 2005 at 08:05:30PM +0200, matthieu castet wrote:
> Roman Kagan wrote:
> >Hmm, if you use 1007 bytes == 19 cells per iso frame (you don't use
> >padding, do you?) and want 16 iso frames per urb you need buffer size of
> >19 * 16 = 304.  503 shouldn't be a problem too, however, from the
> >aesthetic POV I'd suggest a multiple of iso frame size, say 494 or 513.
> well I need to investigate, I set it to 304 and it work well :)

Wow!  I'm really glad to hear that!  Still, playing with buffer size
would be interesting...

> >Yep, that's the notorious -EILSEQ you were seeing before...
> There no need for the attached patch as -EILSEQ  seems to appear only 
> when the modem failed to fill to urb (so only when the modem send 
> nothing)...

I'm a bit confused.  Have -EILSEQ errors disappeared now?  That is
really surprizing: I don't see anything fundamentally different from USB
POV in my new code as compared to the current CVS code, where you added
that workaround to ignore -EILSEQ errors...

> Also because you mix in your error count urb_submit and urb->status the 
> counter is always 0 or 1...

Right, I didn't realize that there might be a pattern of repetitive
successes on submission and failures on completion.  What would be a
better way to handle this?  Introduce separate counters for subission
and completion?

> Why usbatm_check_usb_errcode is dbg not vdbg : it generate lot's of log...

I'm always bad differentiating between logging levels...  I'll change it
to what you suggest.


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