10 Jan, 2012

1 commit

  • We allocate the "mtd" structure using kzalloc which means we do not have
    to initialize unused MTD function pointers to NULL, since it is safe to
    assume in Linux that NULL contains all zeroes.

    Signed-off-by: Artem Bityutskiy
    Signed-off-by: David Woodhouse

    Artem Bityutskiy
     

01 Nov, 2011

1 commit


25 May, 2011

2 commits

  • This is a trivial patch which removes unnecessary assignment of chip->state
    in put_chip(). It's duplicated.

    Signed-off-by: Tadashi Abe
    Acked-by: Joakim Tjernlund
    Signed-off-by: David Woodhouse

    Tadashi Abe
     
  • cfi erase command hangs up when erase and read contention occurs.
    If read runs at the same address as erase operation, read issues
    Erase-Suspend via get_chip() and the erase goes into sleep in wait queue.
    But in this case, read operation exits by time-out without waking it up.

    I think the other variants (0001, 0020 and lpddr) have the same problem too.
    Tested and verified the patch only on CFI-0002 flash, though.

    Signed-off-by: Tadashi Abe
    Acked-by: Joakim Tjernlund
    Signed-off-by: David Woodhouse

    Tadashi Abe
     

31 Mar, 2011

1 commit


06 Aug, 2010

1 commit


14 May, 2010

1 commit

  • Use kzalloc rather than the combination of kmalloc and memset.

    The semantic patch that makes this change is as follows:
    (http://coccinelle.lip6.fr/)

    //
    @@
    expression x,size,flags;
    statement S;
    @@

    -x = kmalloc(size,flags);
    +x = kzalloc(size,flags);
    if (x == NULL) S
    -memset(x, 0, size);
    //

    Signed-off-by: Julia Lawall
    Signed-off-by: David Woodhouse

    Julia Lawall
     

10 May, 2010

2 commits

  • Conflicts:
    drivers/mtd/mtdcore.c

    Pull in the bdi fixes and ARM platform changes that other outstanding
    patches depend on.

    David Woodhouse
     
  • The use of a memcpy() during a spinlock operation will cause very long
    thread context switch delays if the flash chip bandwidth is low and the
    data to be copied large, because a spinlock will disable preemption.

    For example: A flash with 6,5 MB/s bandwidth will cause under ubifs,
    which request sometimes 128 KiB (the flash erase size), a preemption delay of
    20 milliseconds. High priority threads will not be served during this
    time, regardless whether this threads access the flash or not. This behavior
    breaks real time.

    The patch changes all the use of spin_lock operations for xxxx->mutex
    into mutex operations, which is exact what the name says and means.

    I have checked the code of the drivers and there is no use of atomic
    pathes like interrupt or timers. The mtdoops facility will also not be used
    by this drivers. So it is dave to replace the spin_lock against mutex.

    There is no performance regression since the mutex is normally not
    acquired.

    Changelog:
    06.03.2010 First release
    26.03.2010 Fix mutex[1] issue and tested it for compile failure

    Signed-off-by: Stefani Seibold
    Signed-off-by: Artem Bityutskiy
    Signed-off-by: David Woodhouse

    Stefani Seibold
     

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
     

09 Nov, 2009

1 commit


11 Jan, 2009

1 commit


05 Jan, 2009

3 commits

  • We have two components to manage LPDDR flash memories in Linux.
    1. It is a driver for chip probing and reading its capabilities
    2. It is a device operations driver.

    Signed-off-by: Alexey Korolev
    Acked-by: Jared Hulbert
    Signed-off-by: David Woodhouse

    Alexey Korolev
     
  • Driver which handles device command operation.
    Details on device operations are available here:
    http://www.numonyx.com/Documents/Datasheets/DS-315768_Velocity-Discrete.pdf

    Signed-off-by: Alexey Korolev
    Acked-by: Jared Hulbert
    Signed-off-by: David Woodhouse

    Alexey Korolev
     
  • LPDDR flash chips are based on completely new kind of chips probing.
    Device capabilities are available via special request.
    We sent field request command which contains Major and Minor numbers - and
    recieve corresponend value.
    All requests are performed within PFOW window.
    Detailed information about qinfo records can be found here:
    http://www.numonyx.com/Documents/Datasheets/DS-315768_Velocity-Discrete.pdf

    Signed-off-by: Alexey Korolev
    Acked-by: Jared Hulbert
    Signed-off-by: David Woodhouse

    Alexey Korolev