DWC OTG TX path optimisation for 11-current

Hans Petter Selasky hps at selasky.org
Wed Aug 12 13:34:27 UTC 2015


On 07/31/15 17:11, Svatopluk Kraus wrote:
> Note that I got about 24000 interrupts per a second during buildworld
> too. If I remember it correctly, it was about 4000 before r285935.
> When the trigger is pulled, the count is changing (in range of 4000 to
> 21000). It looks like something is taking more time (interrupt
> servicing probably). According to "systat -v", disk is going to be
> 100% (and more) busy very often for example.

Hi,

Finally my RPI-2 arrived :-)

After r285935 we are polling for data more frequently, so the IRQ rate 
will go up. 3x 8000 IRQs/second would be normal to query the device 
every 125us, which the EHCI does.

Can you give me some more information about your setup, so that I can 
reproduce it?

How many USB devices are there in total, and how are the filesystems 
mounted?

--HPS


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