[Letux-kernel] USB3-port on OMAP5432EVM

Tony Lindgren tony at atomide.com
Thu Feb 16 16:16:42 CET 2017


* 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?

> > 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 :)

Regards,

Tony


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