1. 09 Aug, 2018 1 commit
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  3. 15 Jul, 2018 2 commits
  4. 14 Jul, 2018 19 commits
  5. 13 Jul, 2018 15 commits
  6. 12 Jul, 2018 2 commits
    • Joel Fernandes (Google)'s avatar
      tracing: Reorder display of TGID to be after PID · f8494fa3
      Joel Fernandes (Google) authored
      Currently ftrace displays data in trace output like so:
      
                                             _-----=> irqs-off
                                            / _----=> need-resched
                                           | / _---=> hardirq/softirq
                                           || / _--=> preempt-depth
                                           ||| /     delay
                  TASK-PID   CPU    TGID   ||||    TIMESTAMP  FUNCTION
                     | |       |      |    ||||       |         |
                  bash-1091  [000] ( 1091) d..2    28.313544: sched_switch:
      
      However Android's trace visualization tools expect a slightly different
      format due to an out-of-tree patch patch that was been carried for a
      decade, notice that the TGID and CPU fields are reversed:
      
                                             _-----=> irqs-off
                                            / _----=> need-resched
                                           | / _---=> hardirq/softirq
                                           || / _--=> preempt-depth
                                           ||| /     delay
                  TASK-PID    TGID   CPU   ||||    TIMESTAMP  FUNCTION
                     | |        |      |   ||||       |         |
                  bash-1091  ( 1091) [002] d..2    64.965177: sched_switch:
      
      From kernel v4.13 onwards, during which TGID was introduced, tracing
      with systrace on all Android kernels will break (most Android kernels
      have been on 4.9 with Android patches, so this issues hasn't been seen
      yet). From v4.13 onwards things will break.
      
      The chrome browser's tracing tools also embed the systrace viewer which
      uses the legacy TGID format and updates to that are known to be
      difficult to make.
      
      Considering this, I suggest we make this change to the upstream kernel
      and backport it to all Android kernels. I believe this feature is merged
      recently enough into the upstream kernel that it shouldn't be a problem.
      Also logically, IMO it makes more sense to group the TGID with the
      TASK-PID and the CPU after these.
      
      Link: http://lkml.kernel.org/r/20180626000822.113931-1-joel@joelfernandes.org
      
      Cc: jreck@google.com
      Cc: tkjos@google.com
      Cc: stable@vger.kernel.org
      Fixes: 441dae8f ("tracing: Add support for display of tgid in trace output")
      Signed-off-by: default avatarJoel Fernandes (Google) <joel@joelfernandes.org>
      Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      f8494fa3
    • Wolfram Sang's avatar
      i2c: recovery: if possible send STOP with recovery pulses · abe41184
      Wolfram Sang authored
      I2C clients may misunderstand recovery pulses if they can't read SDA to
      bail out early. In the worst case, as a write operation. To avoid that
      and if we can write SDA, try to send STOP to avoid the
      misinterpretation.
      Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
      Reviewed-by: default avatarPeter Rosin <peda@axentia.se>
      Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
      Cc: stable@kernel.org
      abe41184