21 Jan, 2011

1 commit


30 Mar, 2010

1 commit

  • …it 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: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

07 Sep, 2009

1 commit


27 Aug, 2009

2 commits

  • If we change the inverted attribute to another value, the LED will not be
    inverted until we change the GPIO state.

    Signed-off-by: Thadeu Lima de Souza Cascardo
    Cc: Samuel R. C. Vale
    Cc: Richard Purdie
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Thadeu Lima de Souza Cascardo
     
  • When setting the same GPIO number, multiple IRQ shared requests will be
    done without freing the previous request. It will also try to free a
    failed request or an already freed IRQ if 0 was written to the gpio file.

    All these oops and leaks were fixed with the following solution: keep the
    previous allocated GPIO (if any) still allocated in case the new request
    fails. The alternative solution would desallocate the previous allocated
    GPIO and set gpio as 0.

    Signed-off-by: Thadeu Lima de Souza Cascardo
    Signed-off-by: Samuel R. C. Vale
    Cc: Richard Purdie
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Thadeu Lima de Souza Cascardo
     

06 Apr, 2009

1 commit

  • The gpio led trigger will allow leds to be triggered by
    gpio events.

    When we give the led a gpio number, the trigger will
    request_irq() on that so we don't have to keep polling
    for gpio state.

    It's useful for usecases as n810's keypad leds that could
    be triggered by the gpio event generated when user slides
    up to show the keypad.

    We also provide means for userland to tell us what is the
    desired brightness for that special led when it goes on
    so userland could use information from ambient light sensors
    and not set led brightness too high if it's not necessary.

    Signed-off-by: Felipe Balbi
    Signed-off-by: Richard Purdie

    Felipe Balbi