High CPU load produced by USB (DW2)

Minas Harutyunyan Minas.Harutyunyan at synopsys.com
Tue Mar 6 00:09:08 PST 2018


Hi,

On 3/6/2018 10:45 AM, Minas Harutyunyan wrote:
> Hi,
> 
> On 3/5/2018 11:14 PM, Marek Vasut wrote:
>> On 02/20/2018 06:51 AM, Minas Harutyunyan wrote:
>> [...]
>>>>>> Is there a way to reduce that or is that the absolute minimum in HS mode?
>>>>>>
>>>>> We already discussed, in this email thread earlier, why SOF interrupts
>>>>> required and unmasked.
>>>>> Only in case when connected device with CTRL+BLK EP's only (like flash
>>>>> drive) and directly connected to cores root HUB, SOF's will be masked.
>>>>
>>>> That's the setup I have on Altera SoCFPGA, yet the SOFs are still present.
>>>>
>>> Could you please send verbose lsusb on connected to dwc2 device
>>
>> See attached
>>
>>> and driver debug log.
>>
>> What exactly do you mean by this one ?
> Enable debugging messages and verbose debugging messages for dwc2 from
> make menuconfig. Provide dmesg starting from dwc2 load till HS device
> connected to dwc2 port and enumerated.
> 
> Thanks,
> Minas
> 
>>
> 
> 
Driver debug log not required.
Based on lsusb output: to dwc2 port connected "Standard Microsystems 
Corp. USB 2.0 Hub" to which connected your HS device "SanDisk Corp. 
Ultra". Because of connected HUB, which have periodic endpoint 
(Interrupt IN EP1) like all HUB's, dwc2 forced in Buffer DMA mode unmask 
SOF interrupts.

Thanks,
Minas






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