Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1378723

RE: [PATCH v4 2/2] usb: dwc3: add debugfs node to dump FIFO/Queue available space

Show all headers | View raw

> Hi,
> 
> "Du, Changbin" <changbin.du@intel.com> writes:
> >> > At last, comparing with the FIFO/Queue info, I think software transfer
> >> > Requests list, TRBs info, EVENTs history are much more useful for
> >> debugging
> >> > the driver. If you can also add these info to each EP folder, that is
> awesome!
> >> > :)
> >>
> >> I'll think about adding these but for the lifetime of requests and trbs
> >> and events, etc, we have tracepoints for that. I usually do the
> >> following when debugging:
> >>
> >> # mount -t debugfs none /sys/kernel/debug
> >> # cd /sys/kernel/debug/tracing
> >> # echo 2048 > buffer_size_kb
> >> # echo 1 > events/dwc3/enable
> >>
> >> (do something to break it)
> >>
> >> # cp trace /mnt/sdcard # or something like that
> >>
> >> then read the file. You can make it as large or as small as you like
> >> (given some constraints, of course ;-) but I've had no issues allocating
> >> 128MiB in the past.
> >>
> >> --
> >> Balbi
> >
> > Thanks for the sharing, this is a good approach to capture dynamic
> > behaviors. But a dump of current state has below advantages:
> > 1. a quick view for the pending transfers. Then we can quickly
> >      checking the transfer status.
> > 2. no side-effect. This is important in some case. We usually
> >     encounter some transfer issues but very hard to reproduce
> >     it. But we cannot enable trace all the time since performance
> >     concern. Then I thought it was so great if I can have a look for
> >     the trb status. :)
> 
> yeah, okay. We can definitely add "current state" of almost anything,
> but if you need history, then debugfs is not the best interface and I'd
> point you to tracepoints ;-)
> 
> I'll think about how I can add TRB state, seems like we'd need to dump
> the entire endpoint ring, and that's 256 TRBs per endpoint :-p Then we
> also need to know endpoint's dequeue and enqueue pointer. Oh well, let
> me get this first setup of files out of the way, then we can add more
> later much more easily.
> 
> --
> Balbi

Okay, things need finish step by step. Thank you, Balbi. ( ゜- ゜)つロ

Best Regards,
Du, Changbin

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH] usb: dwc3: add debugfs node to dump FIFO/Queue available space changbin.du@intel.com - 2016-04-06 10:40 +0200
  Re: [PATCH] usb: dwc3: add debugfs node to dump FIFO/Queue available  space Greg KH <gregkh@linuxfoundation.org> - 2016-04-06 11:30 +0200
    RE: [PATCH] usb: dwc3: add debugfs node to dump FIFO/Queue  available space "Du, Changbin" <changbin.du@intel.com> - 2016-04-06 13:40 +0200
      RE: [PATCH] usb: dwc3: add debugfs node to dump FIFO/Queue available space Felipe Balbi <balbi@kernel.org> - 2016-04-06 14:30 +0200
    [PATCH v2 0/3] Improvement, fix and new entry for dwc3 debugfs changbin.du@intel.com - 2016-04-06 18:00 +0200
      [PATCH v2 3/3] usb: dwc3: add debugfs node to dump FIFO/Queue available space changbin.du@intel.com - 2016-04-06 18:00 +0200
      Re: [PATCH v2 0/3] Improvement, fix and new entry for dwc3 debugfs Felipe Balbi <balbi@kernel.org> - 2016-04-07 07:10 +0200
        RE: [PATCH v2 0/3] Improvement, fix and new entry for dwc3 debugfs "Du, Changbin" <changbin.du@intel.com> - 2016-04-07 07:30 +0200
          RE: [PATCH v2 0/3] Improvement, fix and new entry for dwc3 debugfs Felipe Balbi <balbi@kernel.org> - 2016-04-07 07:30 +0200
        [PATCH v3 0/2] Add a new debugfs entry to dump FIFO/Queue available space changbin.du@intel.com - 2016-04-08 11:50 +0200
          [PATCH v3 1/2] usb: dwc3: make dwc3_debugfs_init return value be void changbin.du@intel.com - 2016-04-08 11:50 +0200
            Re: [PATCH v3 1/2] usb: dwc3: make dwc3_debugfs_init return value be void Felipe Balbi <balbi@kernel.org> - 2016-04-11 10:20 +0200
              RE: [PATCH v3 1/2] usb: dwc3: make dwc3_debugfs_init return value  be void "Du, Changbin" <changbin.du@intel.com> - 2016-04-11 13:20 +0200
                RE: [PATCH v3 1/2] usb: dwc3: make dwc3_debugfs_init return value be void Felipe Balbi <balbi@kernel.org> - 2016-04-11 13:30 +0200
                [PATCH v4 0/2] Add a new debugfs entry to dump FIFO/Queue available space changbin.du@intel.com - 2016-04-12 13:30 +0200
                [PATCH v4 2/2] usb: dwc3: add debugfs node to dump FIFO/Queue available space changbin.du@intel.com - 2016-04-12 13:30 +0200
                Re: [PATCH v4 2/2] usb: dwc3: add debugfs node to dump FIFO/Queue  available space Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2016-04-12 15:00 +0200
                RE: [PATCH v4 2/2] usb: dwc3: add debugfs node to dump FIFO/Queue  available space "Du, Changbin" <changbin.du@intel.com> - 2016-04-14 05:30 +0200
                Re: [PATCH v4 2/2] usb: dwc3: add debugfs node to dump FIFO/Queue available space Felipe Balbi <balbi@kernel.org> - 2016-04-14 10:10 +0200
                RE: [PATCH v4 2/2] usb: dwc3: add debugfs node to dump FIFO/Queue  available space "Du, Changbin" <changbin.du@intel.com> - 2016-04-14 13:20 +0200
                RE: [PATCH v4 2/2] usb: dwc3: add debugfs node to dump FIFO/Queue available space Felipe Balbi <balbi@kernel.org> - 2016-04-14 13:30 +0200
                RE: [PATCH v4 2/2] usb: dwc3: add debugfs node to dump FIFO/Queue  available space "Du, Changbin" <changbin.du@intel.com> - 2016-04-14 13:40 +0200
                RE: [PATCH v4 2/2] usb: dwc3: add debugfs node to dump FIFO/Queue available space Felipe Balbi <balbi@kernel.org> - 2016-04-14 13:50 +0200
                RE: [PATCH v4 2/2] usb: dwc3: add debugfs node to dump FIFO/Queue  available space "Du, Changbin" <changbin.du@intel.com> - 2016-04-14 14:00 +0200
                [PATCH v4 1/2] usb: dwc3: make dwc3_debugfs_init return value be void changbin.du@intel.com - 2016-04-12 13:30 +0200
          [PATCH v3 2/2] usb: dwc3: add debugfs node to dump FIFO/Queue available space changbin.du@intel.com - 2016-04-08 11:50 +0200

csiph-web