[Letux-kernel] USB3-port on OMAP5432EVM

Roger Quadros rogerq at ti.com
Fri Feb 17 09:39:18 CET 2017


On 16/02/17 17:16, Tony Lindgren wrote:
> * Roger Quadros <rogerq at ti.com> [170216 05:44]:
>> +Chanwoo
>>
>> On 15/02/17 23:36, Tony Lindgren wrote:
>>> * Tony Lindgren <tony at atomide.com> [170215 13:01]:
>>>> * Roger Quadros <rogerq at ti.com> [170214 01:44]:
>>>>> You can enable dwc3 trace events.
>>>>>
>>>>> cd /sys/kernel/debug/tracing
>>>>> echo 1 > events/dwc3/enable
>>>>> echo 0 > events/dwc3/dwc3_readl/enable
>>>>> echo 0 > events/dwc3/dwc3_writel/enable
>>>>> echo 1 > free_buffer
>>>>> echo 2048 > buffer_size_kb
>>>>
>>>> For me the issue was I had to change my sysfs scripts to start doing
>>>> echo -n instead of just echo. Things are working for me now with Linux
>>>> next.
>>>
>>> Then in host mode after connecting a device, I see the following warnings
>>> with Linux next and lockdep enabled if host mode is forced with
>>> dr_mode = "host":
> 
> BTW is dr_mode = "host" still needed or is the role switching close to
> working now?

dual-role is still under review.
https://lkml.org/lkml/2017/2/16/254

I haven't tested it on omap5-uevm. Will keep it in mind.

> 
>>> CONFIG_DEBUG_LOCKDEP=y
>>> CONFIG_DEBUG_ATOMIC_SLEEP=y
>>
>> Looks like extcon is calling the notifiers while atomic. (spinlocks held, IRQs disabled?)
>> Does this needs to be fixed at extcon layer or dwc3-omap should
>> execute the mailbox in a workqueue?
> 
> Sounds like changing it in extcon might break unknown other drivers :)

OK.

-- 
cheers,
-roger


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