Date: Mon, 03 Aug 2009 15:03:07 -0700 From: Julian Elischer <julian@elischer.org> To: Hans Petter Selasky <hselasky@c2i.net> Cc: Alexander Best <alexbestms@math.uni-muenster.de>, freebsd-usb@freebsd.org Subject: Re: kernel debugger and usb keyboard Message-ID: <4A775E9B.8070900@elischer.org> In-Reply-To: <200908032127.32353.hselasky@c2i.net> References: <permail-20090803185516f7e55a9d00006928-a_best01@message-id.uni-muenster.de> <200908032127.32353.hselasky@c2i.net>
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Hans Petter Selasky wrote: > On Monday 03 August 2009 20:55:16 Alexander Best wrote: >> just tried settings `sysctl debug.kdb.panic = 1`. if i use this way to >> enter the kernel debugger my usb keyboard works. if i type "continue" >> however the kernel panics and the kernel debugger gets yet entered again, >> but without the keyboard working. > > The USB controller which the keyboard is hooked onto will not work after panic > has been entered, due to some state not being cleaned up. > > To increase the chance of the keyboard working on a panic, connect the > keyboard to a separate USB controller. > >> i don't know how to produce backtraces since the keyboard doesn't work. > > Ok. > >> the other way of entering the debugger without my keyboard working was to >> simple press "ctrl+ast+esc". try entering it from the sysctl debug.kdb.enter (set it to 1) > > Yes, because most likely the DDB is entered directly from the USB keyboard > code, and the USB stack does not allow function recursion in that case! > > --HPS > > _______________________________________________ > freebsd-usb@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-usb > To unsubscribe, send any mail to "freebsd-usb-unsubscribe@freebsd.org"
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