Re: [PATCH] usb: dwc3: gadget: Disable gadget IRQ during pullup disable

[Jack Pham <jackp@codeaurora.org>]

On Fri, Jun 11, 2021 at 10:23:43AM +0300, Felipe Balbi wrote:
> Wesley Cheng <wcheng@codeaurora.org> writes:

<snip>

> > Hi Felipe,
> >
> > Let me share the ftrace snippets as well:
> >
> > USB FTRACE:
> >
> > <idle>-0    [002]   304.567900:  dwc3_gadget_ep_cmd name=ep0out cmd=1030  param0=0  param1=4026523648  param2=0  cmd_status=0
> > <idle>-0    [004]   304.583225:  dwc3_gadget_ep_cmd name=ep1out cmd=134152  param0=0  param1=0  param2=0  cmd_status=0
> >
> > //We don't have any logging in pullup disable, but this is when that
> > occurs, as we start to see -ESHUTDOWN statuses due to stop active
> > transfer.
> 
> argh, maybe we should add :-)
> 
> I noticed that the logs here look different. Did you modify dwc3 trace
> events or is it a special tracer (just curious)? Anyway...

These logs come from an internal tool that extracts the traces from a
complete RAM dump from a crashed device. One of the limitations is that
the script doesn't (yet) understand the event printk-formats so we're
left with just the raw field contents of the TP_STRUCT__entry. Not
pretty at all but it's *lot* better than nothing especially for
post-mortem analysis.

Yes there is crash-utility [1] which does all of this already but
logistically our internal tooling is not very well equipped (i.e. is
Windows-based) to make use of this, not without going through some
hoops. Been meaning to play around with it some more though to reduce
the need for our home-rolled solution.

[1] https://github.com/crash-utility

> > <idle>-0    [004]   304.583237:  dwc3_gadget_giveback name=ep1out req=1243650560  actual=0  length=16384  status=4294967188  zero=0 short_not_ok=0  no_interrupt=0
> > <idle>-0    [004]   304.583275:  dwc3_gadget_giveback name=ep1out req=1243645440  actual=0  length=16384  status=4294967188  zero=0 short_not_ok=0  no_interrupt=0
> > <idle>-0    [004]   304.583282:  dwc3_gadget_giveback name=ep1out req=1243648256  actual=0  length=16384  status=4294967188  zero=0 short_not_ok=0  no_interrupt=0
> > <idle>-0    [004]   304.583312:  dwc3_gadget_giveback name=ep1out req=4075146240  actual=0  length=16384  status=4294967188  zero=0 short_not_ok=0  no_interrupt=0
> > ...
> > //USB gadget disconnect is printed AFTER the pullup(0) routine is complete.
> > <idle>-0    [004]   304.584240:  usb_gadget_disconnect   speed=3 max_speed=6  state=7  mA=500  sg_supported=1  is_otg=0 is_a_peripheral=0  b_hnp_enable=0  a_hnp_support=0 hnp_polling_support=0  host_request_flag=0  quirk_ep_out_aligned_size=0 quirk_altset_not_supp=0  quirk_stall_not_supp=0  quirk_zlp_not_supp=0 is_selfpowered=0  deactivated=0  connected=1  ret=4294967186
> >
> > ---------------------------------------------------------
> > CPU2 SCHED FTRACE:
> >
> > kworker/u16:5-192    [002]   304.583354:  irq_handler_entry   irq=343 name=dwc3-msm
> > kworker/u16:5-192    [002]   304.583356:  irq_handler_exit   irq=343 ret=0
> > kworker/u16:5-192    [002]   304.583358:  irq_handler_entry   irq=343 name=dwc3
> > kworker/u16:5-192    [002]   304.583366:  irq_handler_exit   irq=343 ret=2
> > kworker/u16:5-192    [002]   304.583377:  sched_wakeup comm=irq/343-dwc3  pid=20174  prio=100  success=1  target_cpu=2
> > kworker/u16:5-192   [002]  304.583411: sched_switch: prev_comm=kworker/u16:5 prev_pid=192 prev_prio=120 prev_state=R ==> next_comm=irq/343-dwc3 next_pid=20174 next_prio=100
> > irq/343-dwc3-20174    [002]   304.583454:  irq_handler_entry   irq=343 name=dwc3-msm
> > irq/343-dwc3-20174    [002]   304.583455:  irq_handler_exit   irq=343 ret=0
> > irq/343-dwc3-20174    [002]   304.583458:  irq_handler_entry   irq=343 name=dwc3
> > irq/343-dwc3-20174    [002]   304.583465:  irq_handler_exit   irq=343 ret=2

Jack
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