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  1. 25 8月, 2014 3 次提交
    • L
      pwm: imx: Avoid sample FIFO overflow for i.MX PWM version2 · 137fd45f
      由 Liu Ying 提交于 
      The i.MX PWM version2 is embedded in several i.MX SoCs, such as i.MX27,
i.MX51 and i.MX6SL.  There is a 4-word (16 bit) sample FIFO in this IP.
Each FIFO slot determines the duty period of a PWM waveform in one full
cycle.  The IP spec mentions that we should not write a fourth sample
because the FIFO will become full and triggers a FIFO write error (FWE)
which will prevent the PWM from starting once it is enabled.  In order
to avoid any sample FIFO overflow issue, this patch clears all sample
FIFO by doing software reset in the configuration hook when the
controller is disabled or waits for a full PWM cycle to get a
relinquished FIFO slot when the controller is enabled and the FIFO is
fully loaded.

The FIFO overflow issue can be reproduced by the following commands on
the i.MX6SL EVK platform, assuming we use PWM2 for the debug LED which
is driven by the pin HSIC_STROBE and the maximal brightness is 255.

	echo 0   > /sys/class/leds/user/brightness
	echo 0   > /sys/class/leds/user/brightness
	echo 0   > /sys/class/leds/user/brightness
	echo 0   > /sys/class/leds/user/brightness
	echo 255 > /sys/class/leds/user/brightness

Here, FWE happens (PWMSR register reads 0x58) and the LED can not be
lighten.

Another way to reproduce the FIFO overflow issue is to run this script:

	while true;
		do echo 255 > /sys/class/leds/user/brightness;
	done

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Lothar Waßmann <LW@KARO-electronics.de>
Cc: linux-pwm@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NLiu Ying <Ying.Liu@freescale.com>
Acked-by: NShawn Guo <shawn.guo@freescale.com>
Signed-off-by: NThierry Reding <thierry.reding@gmail.com>
      137fd45f
    • L
      pwm: imx: Cleanup indentation for register definitions · 40f260c2
      由 Liu Ying 提交于 
      This patch contains no logic change to cleanup indentation for register
definitions only.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Lothar Waßmann <LW@KARO-electronics.de>
Cc: linux-pwm@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NLiu Ying <Ying.Liu@freescale.com>
Acked-by: NShawn Guo <shawn.guo@freescale.com>
Signed-off-by: NThierry Reding <thierry.reding@gmail.com>
      40f260c2
    • L
      pwm: imx: Fix the macro MX3_PWMCR_PRESCALER(x) definition · bd59bdc8
      由 Liu Ying 提交于 
      This patch adds missing parentheses around the argument of the macro
MX3_PWMCR_PRESCALER(x) to avoid any potential macro expansion issue.
Reported-by: NLothar Waßmann <LW@KARO-electronics.de>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Lothar Waßmann <LW@KARO-electronics.de>
Cc: linux-pwm@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NLiu Ying <Ying.Liu@freescale.com>
Acked-by: NShawn Guo <shawn.guo@freescale.com>
Signed-off-by: NThierry Reding <thierry.reding@gmail.com>
      bd59bdc8
  3. 07 8月, 2014 1 次提交
  5. 28 4月, 2014 1 次提交
  7. 08 10月, 2013 2 次提交
  9. 12 6月, 2013 1 次提交
  11. 18 5月, 2013 1 次提交
  13. 02 4月, 2013 1 次提交
  15. 23 1月, 2013 1 次提交
  17. 06 12月, 2012 1 次提交
  19. 29 11月, 2012 3 次提交
  21. 12 9月, 2012 7 次提交
  23. 23 7月, 2012 1 次提交
  25. 03 7月, 2012 1 次提交
  27. 01 2月, 2012 1 次提交
  29. 19 12月, 2011 1 次提交
  31. 09 12月, 2011 1 次提交
  33. 24 8月, 2011 1 次提交
  35. 07 7月, 2011 1 次提交
  37. 10 6月, 2011 1 次提交
  39. 13 1月, 2011 1 次提交
  41. 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
  43. 04 12月, 2009 1 次提交
  45. 14 8月, 2009 1 次提交
  47. 07 8月, 2009 1 次提交
  49. 07 5月, 2009 1 次提交
  51. 13 3月, 2009 1 次提交