src/patches/suse-2.6.27.25/patches.arch/ppc-spufs-04-sputrace-Don-t-block-until-the-read.patch

   1 Subject: Don't block until the read buffer is full
   2 From: Jeremy Kerr <jk@ozlabs.org>
   3 References: 447133 - LTC50070
   4
   5 Currently, read() on the sputrace buffer will only return data when
   6 the user buffer is exhausted. This may mean that we never see the
   7 end of the event log, unless we read() with exactly the right-sized
   8 buffer.
   9
  10 This change makes sputrace_read not block if we have data ready to
  11 return.
  12
  13 Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
  14 Signed-off-by: Olaf Hering <olh@suse.de>
  15 ---
  16  arch/powerpc/platforms/cell/spufs/sputrace.c |    5 +++++
  17  1 file changed, 5 insertions(+)
  18
  19 --- a/arch/powerpc/platforms/cell/spufs/sputrace.c
  20 +++ b/arch/powerpc/platforms/cell/spufs/sputrace.c
  21 @@ -80,6 +80,11 @@ static ssize_t sputrace_read(struct file
  22                 char tbuf[128];
  23                 int width;
  24
  25 +               /* If we have data ready to return, don't block waiting
  26 +                * for more */
  27 +               if (cnt > 0 && sputrace_used() == 0)
  28 +                       break;
  29 +
  30                 error = wait_event_interruptible(sputrace_wait,
  31                                                  sputrace_used() > 0);
  32                 if (error)