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  1. 29 1月, 2014 2 次提交
    • D
      watchdog: s3c2410_wdt: Handle rounding a little better for timeout · 17862440
      由 Doug Anderson 提交于 
      The existing watchdog timeout worked OK but didn't deal with
rounding in an ideal way when dividing out all of its clocks.

Specifically if you had a timeout of 32 seconds and an input clock of
66666666, you'd end up setting a timeout of 31.9998 seconds and
reporting a timeout of 31 seconds.

Specifically DBG printouts showed:
  s3c2410wdt_set_heartbeat: count=16666656, timeout=32, freq=520833
  s3c2410wdt_set_heartbeat: timeout=32, divisor=255, count=16666656 (0000ff4f)
and the final timeout reported to the user was:
  ((count / divisor) * divisor) / freq
  (0xff4f * 255) / 520833 = 31 (truncated from 31.9998)
the technically "correct" value is:
  (0xff4f * 255) / (66666666.0 / 128) = 31.9998

By using "DIV_ROUND_UP" we can be a little more correct.
  s3c2410wdt_set_heartbeat: count=16666688, timeout=32, freq=520834
  s3c2410wdt_set_heartbeat: timeout=32, divisor=255, count=16666688 (0000ff50)
and the final timeout reported to the user:
  (0xff50 * 255) / 520834 = 32
the technically "correct" value is:
  (0xff50 * 255) / (66666666.0 / 128) = 32.0003

We'll use a DIV_ROUND_UP to solve this, generally erroring on the side
of reporting shorter values to the user and setting the watchdog to
slightly longer than requested:
* Round input frequency up to assume watchdog is counting faster.
* Round divisions by divisor up to give us extra time.

At the same time we can avoid a for loop by just doing the right math.
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>
      17862440
    • D
      watchdog: s3c2410_wdt: Only register for cpufreq on ARM_S3C24XX_CPUFREQ · 0f1dd98d
      由 Doug Anderson 提交于 
      On modern SoCs the watchdog timer is parented on a clock that doesn't
change every time we have a cpufreq change.  That means we don't need
to constantly adjust the watchdog timer, so avoid registering for and
dealing with cpufreq transitions unless we've actually got
CONFIG_ARM_S3C24XX_CPUFREQ defined.

Note that this is more than just an optimization.  The s3c2410
watchdog driver actually pats the watchdog on every CPU frequency
change.  On modern systems these happen many times per second (even in
a system where "nothing" is happening).  That effectively makes any
userspace watchdog program useless (the watchdog is constantly patted
by the kernel).  If we need ARM_S3C24XX_CPUFREQ defined on a
multiplatform kernel we'll need to make sure that kernel supports
common clock and change this to user common clock framework.
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NTomasz Figa <t.figa@samsung.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>
      0f1dd98d
  3. 18 11月, 2013 1 次提交
    • J
      watchdog: Get rid of MODULE_ALIAS_MISCDEV statements · 487722cf
      由 Jean Delvare 提交于 
      I just can't find any value in MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR)
and MODULE_ALIAS_MISCDEV(TEMP_MINOR) statements.

Either the device is enumerated and the driver already has a module
alias (e.g. PCI, USB etc.) that will get the right driver loaded
automatically.

Or the device is not enumerated and loading its driver will lead to
more or less intrusive hardware poking. Such hardware poking should be
limited to a bare minimum, so the user should really decide which
drivers should be tried and in what order. Trying them all in
arbitrary order can't do any good.

On top of that, loading that many drivers at once bloats the kernel
log. Also many drivers will stay loaded afterward, bloating the output
of "lsmod" and wasting memory. Some modules (cs5535_mfgpt which gets
loaded as a dependency) can't even be unloaded!

If defining char-major-10-130 is needed then it should happen in
user-space.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Acked-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Mike Frysinger <vapier.adi@gmail.com>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Cc: Jim Cromie <jim.cromie@gmail.com>
      487722cf
  5. 11 9月, 2013 2 次提交
  7. 12 7月, 2013 2 次提交
  9. 19 6月, 2013 1 次提交
  11. 09 5月, 2013 1 次提交
  13. 01 3月, 2013 2 次提交
  15. 20 12月, 2012 1 次提交
  17. 29 11月, 2012 3 次提交
  19. 23 7月, 2012 1 次提交
  21. 23 5月, 2012 2 次提交
  23. 28 3月, 2012 4 次提交
  25. 29 2月, 2012 1 次提交
  27. 06 1月, 2012 1 次提交
  29. 17 11月, 2011 1 次提交
  31. 06 11月, 2011 1 次提交
  33. 22 7月, 2011 1 次提交
  35. 29 3月, 2011 1 次提交
  37. 16 3月, 2011 1 次提交
  39. 09 8月, 2010 1 次提交
    • W
      watchdog: s3c2410_wdt - Fix removing of platform device · 9a372563
      由 Wim Van Sebroeck 提交于 
      When removing the watchdog platform device, we need to
disable the access to userspace first. It makes no sense
to remove the drivers clock, irq's, ... and then disable
userspace access.
the order of removal has also been changed so that it
is the reverse of probing (this way the clock is also
disabled sooner).

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>
      9a372563
  41. 25 5月, 2010 2 次提交
  43. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      由 Tejun Heo 提交于 
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  45. 24 12月, 2009 1 次提交
  47. 04 12月, 2009 1 次提交
  49. 18 6月, 2009 1 次提交
  51. 30 10月, 2008 1 次提交
  53. 29 10月, 2008 1 次提交
  55. 27 8月, 2008 2 次提交