On Thu, Jul 25, 2013 at 10:24 PM, Alan Stern <st...@rowland.harvard.edu> wrote:
> On Thu, 25 Jul 2013, James Stone wrote:
>
>> On Thu, Jul 25, 2013 at 7:26 PM, Alan Stern <st...@rowland.harvard.edu> 
>> wrote:
>> > On Thu, 25 Jul 2013, James Stone wrote:
>> >
>> >> > Please try the patch from here:
>> >> >
>> >> >         http://marc.info/?l=linux-usb&m=137476385206265&w=2
>> >> >
>> >> > instead of the one I sent to you yesterday.  I think it will fix this
>> >> > problem.
>> >> >
>> >> > Alan Stern
>> >> >
>> >>
>> >> Perfect! All fixed!
>> >
>> > Can you provide a usbmon trace showing the start of a session using the
>> > new patch?
>> >
>> > Alan Stern
>> >
>>
>> Sure - will send off list. The only slight difference I can see is
>> that maybe the 3.10 uses slightly higher CPU load than 3.5 at the
>> ridiculously low latency of 64 frames/period duplex.
>
> With the new patch, what you actually get is 44.1 frames/period (on
> average).  That's quite sustainable.
>
> However, something's not working right.  The number of packets in each
> playback URB changes each time the URB is reused!  That's not supposed
> to happen.  The number of packets should remain fixed while the number
> of samples in each packet changes, based on the feedback info.
>
> I don't get it.  The usbmon trace shows three URBs, and the number of
> packets goes like this:
>
>         8 8 8   8 4 8   4 8 3   8 4 8   4 8 3   8 4 8   3 8 4   8 4 8
>         etc...
>
> I'm at a complete loss.  It's not caused by confusion on the feedback
> endpoint; in fact the driver doesn't change this number anywhere once
> it has been set up.  What's going on?
>
> James, please apply the diagnostic patch below on top of everything
> else.  It will write entries into the kernel log which hopefully will
> pin down where this number gets changed.
>
> Another problem, not necessarily a bad one: The feedback data from the
> sound device indicates that its internal clock is actually running at
> 45168 Hz, even though it claims to be running at 44100.
>

OK - here is the output:


Jul 25 23:58:46 blueberry kernel: [   24.440327]     Actions configured
Jul 25 23:59:00 blueberry kernel: [   39.070484] A urb ffff88002e02ca00 cnt 2
Jul 25 23:59:00 blueberry kernel: [   39.071467] B urb ffff8800c9758a00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.071473] C urb ffff8800c9758a00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.071479] A urb ffff8800c9758a00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.072465] B urb ffff8800c9758400 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.072471] C urb ffff8800c9758400 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.072477] A urb ffff8800c9758400 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.072706] B urb ffff88002e02ca00 cnt 2
Jul 25 23:59:00 blueberry kernel: [   39.072711] C urb ffff88002e02ca00 cnt 2
Jul 25 23:59:00 blueberry kernel: [   39.072717] A urb ffff88002e02ca00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.073700] B urb ffff8800c9758a00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.073702] C urb ffff8800c9758a00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.073704] A urb ffff8800c9758a00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.074754] B urb ffff8800c9758400 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.074765] C urb ffff8800c9758400 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.074773] A urb ffff8800c9758400 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.075703] B urb ffff88002e02ca00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.075709] C urb ffff88002e02ca00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.075715] A urb ffff88002e02ca00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.076702] B urb ffff8800c9758a00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.076707] C urb ffff8800c9758a00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.076713] A urb ffff8800c9758a00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.077711] B urb ffff8800c9758400 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.077718] C urb ffff8800c9758400 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.077724] A urb ffff8800c9758400 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.078700] B urb ffff88002e02ca00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.078705] C urb ffff88002e02ca00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.078711] A urb ffff88002e02ca00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.079700] B urb ffff8800c9758a00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.079705] C urb ffff8800c9758a00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.079711] A urb ffff8800c9758a00 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.080747] B urb ffff8800c9758400 cnt 8
Jul 25 23:59:00 blueberry kernel: [   39.080759] C urb ffff8800c9758400 cnt 8


It only wrote this the first time I started jackd. The following
times, I just got this:

Jul 25 23:59:41 blueberry kernel: [   79.775595] ieee80211 phy0:
rt61pci_txdone: Warning - TX status report missed for entry 12
Jul 26 00:01:20 blueberry kernel: [  178.994157] ieee80211 phy0:
rt61pci_txdone: Warning - TX status report missed for entry 15
Jul 26 00:01:24 blueberry kernel: [  182.778798] ieee80211 phy0:
rt61pci_txdone: Warning - TX status report missed for entry 26
Jul 26 00:01:27 blueberry kernel: [  185.970062] ieee80211 phy0:
rt61pci_txdone: Warning - TX status report missed for entry 6
Jul 26 00:01:29 blueberry kernel: [  188.097538] ieee80211 phy0:
rt61pci_txdone: Warning - TX status report missed for entry 28

.. I know there is some talk of wireless functionality interfering
with realtime audio, but not sure this is really related.
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