On Mon, 12 Aug 2013 20:07:29 +0300 Xenia Ragiadakou <burzalodowa@xxxxxxxxx> 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. 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 ;-) -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-trace-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html