On 08/12/2013 08:38 PM, Sarah Sharp wrote:
On Mon, Aug 12, 2013 at 01:18:47PM -0400, Steven Rostedt wrote:
On Mon, 12 Aug 2013 20:07:29 +0300
Xenia Ragiadakou <[email protected]> wrote:
Hi,
I would like to enable a trace event early so that i can view the debug
statements trace generated during usb 3.0 host controller driver
initialization.
I followed the instruction in Documentation/trace/events.txt:
"In order to facilitate early boot debugging, use boot option:
trace_event=[event-list] where event-list is a comma separated list of
events."
and added trace_event=[xhci-hcd:xhci_dbg_init] (where xhci-hcd is the
trace system and xhci_dbg_init is the trace event that i want to enable)
in the boot parameters but it did not work.
More specifically, I added in /etc/grub/default:
GRUB_CMDLINE_LINUX="trace_event=[xhci-hcd:xhci_dbg_init]"
After updating grub, boot parameters in /boot/grub/grub.cfg were changed
into:
linux /boot/vmlinuz-3.9.9.130805+
root=UUID=8af1b7fc-76c1-4cab-97ef-78ef5e29e084 ro
trace_event=[xhci-hcd:xhci_dbg_init] quiet radeon.audio=1
Do I miss something? Any advice would be appreciated.
Hi Ksenia,
I'm guessing that xhci-hcd is a module. Currently we do not have a way
to enable events on module load. We have talked about implementing this
feature, and I believe I even have patches somewhere that do it, but we
never pushed it to completion.
Yes, xhci-hcd is usually complied as a module. You can compile it in,
and some distros chose to do that for performance reasons, but not many.
Xenia, I would suggest for now just configuring the driver as built-in,
so you can test your code.
If you want, I can look for those patches and perhaps they may help
you. I think you are the second person to ask for them. I probably
should do it regardless ;-)
Heh, you should get an OPW intern to complete the patches in the next
round. ;)
Sarah Sharp
Yes, it was actually compiled as module. I will change the config option
into =y instead of =m
and retry it. Thanks a lot!
best regards,
ksenia
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