lkml.org 
[lkml]   [2008]   [Aug]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [git pull] ftrace for v2.6.27

    * Steven Rostedt <srostedt@redhat.com> wrote:

    > Bruce Duncan wrote:
    >> Hi Ingo, Steven, everyone,
    >>
    >> [ Please CC me in replies ]
    >>
    >> I have just tracked down a regression in 2.6.27-rc2 wrt 2.6.26. Commit
    >> 77a2b37d227483fe52aead242652aee406c25bf0 (ftrace: startup tester on
    >> dynamic tracing.) causes my laptop to fail to resume from S3 (it simply
    >> reboots about a second after the resume starts and the display never
    >> shows anything).
    >>
    >> The patch doesn't revert with patch -R (I don't know if there's a
    >> cleverer way to ask git to revert it), but the problem goes away if I
    >> turn off CONFIG_DYNAMIC_FTRACE.
    >>
    >> The commit and bisect log are attached. Please can you help me to debug this?
    >>
    >>
    >>
    >
    > I found that I have a box that displays this bug. Without FTRACE it
    > suspends and resumes fine. With FTRACE enabled, it does not.
    >
    > I'll be actively debugging it now. (unfortunately, as with all new
    > laptops, I don't have a serial for it).

    try latest tip/master plus an USB debug key, then enable
    CONFIG_EARLY_PRINTK_DBGP=y in your .config on the host, add the
    earlyprintk=dbgp,keep boot parameter and reboot [and disable USB for
    good measure]. On the other host you connect to via an USB cable, enable
    USB_SERIAL_DEBUG=y and use /dev/ttyUSB0 with the serial terminal app of
    your choice.

    that, as long as the USB ports are operational, gives a working serial
    console on just about any laptop.

    Ingo


    \
     
     \ /
      Last update: 2008-08-13 17:21    [W:0.023 / U:91.876 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site