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  1. 17 2月, 2010 6 次提交
  3. 16 2月, 2010 11 次提交
  5. 15 2月, 2010 6 次提交
  7. 14 2月, 2010 3 次提交
    • C
      firewire: ohci: retransmit isochronous transmit packets on cycle loss · 7f51a100
      由 Clemens Ladisch 提交于 
      In isochronous transmit DMA descriptors, link the skip address pointer
back to the descriptor itself.  When a cycle is lost, the controller
will send the packet in the next cycle, instead of terminating the
entire DMA program.

There are two reasons for this:

* This behaviour is compatible with the old IEEE1394 stack.  Old
  applications would not expect the DMA program to stop in this case.

* Since the OHCI driver does not report any uncompleted packets, the
  context would stop silently; clients would not have any chance to
  detect and handle this error without a watchdog timer.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>

Pieter Palmers notes:

"The reason I added this retry behavior to the old stack is because some
cards now and then fail to send a packet (e.g. the o2micro card in my
dell laptop).  I couldn't figure out why exactly this happens, my best
guess is that the card cannot fetch the payload data on time.  This
happens much more frequently when sending large packets, which leads me
to suspect that there are some contention issues with the DMA that fills
the transmit FIFO.

In the old stack it was a pretty critical issue as it resulted in a
freeze of the userspace application.

The omission of a packet doesn't necessarily have to be an issue.  E.g.
in IEC61883 streams the DBC field can be used to detect discontinuities
in the stream.  So as long as the other side doesn't bail when no
[packet] is present in a cycle, there is not really a problem.

I'm not convinced though that retrying is the proper solution, but it is
simple and effective for what it had to do.  And I think there are no
reasons not to do it this way.  Userspace can still detect this by
checking the cycle the descriptor was sent in."

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (changelog, comment)
      7f51a100
    • K
      perf top: Fix help text alignment · 1a72cfa6
      由 Kirill Smelkov 提交于 
      Print this:

Mapped keys:
        [d]     display refresh delay.                  (2)
        [e]     display entries (lines).                (46)
        [f]     profile display filter (count).         (5)
        [F]     annotate display filter (percent).      (5%)
        [s]     annotate symbol.                        (NULL)
        [S]     stop annotation.
        [K]     hide kernel_symbols symbols.            (no)
        [U]     hide user symbols.                      (no)
        [z]     toggle sample zeroing.                  (0)
        [qQ]    quit.

instead of:

Mapped keys:
        [d]     display refresh delay.                  (2)
        [e]     display entries (lines).                (46)
        [f]     profile display filter (count).         (5)
        [F]     annotate display filter (percent).      (5%)
        [s]     annotate symbol.                        (NULL)
        [S]     stop annotation.
        [K]     hide kernel_symbols symbols.                    (no)
        [U]     hide user symbols.                      (no)
        [z]     toggle sample zeroing.                  (0)
        [qQ]    quit.
Signed-off-by: NKirill Smelkov <kirr@landau.phys.spbu.ru>
Acked-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100212162059.GA30041@landau.phys.spbu.ru>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      1a72cfa6
    • H
      tracing/kprobes: Fix probe parsing · a9bb18f3
      由 Heiko Carstens 提交于 
      Trying to add a probe like:

  echo p:myprobe 0x10000 > /sys/kernel/debug/tracing/kprobe_events

will fail since the wrong pointer is passed to strict_strtoul
when trying to convert the address to an unsigned long.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100210162346.GA6933@osiris.boeblingen.de.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      a9bb18f3
  9. 13 2月, 2010 9 次提交
  11. 12 2月, 2010 5 次提交