[PULL] IIO fixes for 3.12 set 2

[PULL] IIO fixes for 3.12 set 2

[Jonathan Cameron]

The following changes since commit bda2f8fca20b564ac8edb2b9c080d942c2144359:

  iio:buffer_cb: Add missing iio_buffer_init() (2013-09-21 12:52:50 +0100)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git tags/iio-fixes-for-3.12b

for you to fetch changes up to f09b44ed1d8553c8a91b8de8cfa05f2ea585ab0d:

  iio:magnetometer: Bugfix magnetometer default output registers (2013-09-28 12:03:24 +0100)

----------------------------------------------------------------
Second set of IIO fixes for the 3.12 cycle.

One large fix here to add reference counting to IIO's buffers
in order to prevent them being prematurely freed. The actual code addition
is small but needs to be repeated in a number of different places.

A few small additional fixes:
1) Make sure that debugfs entries are removed early enough to prevent
a race.
2) Drop a stray regulator_put from ad8366 left over from the devm_ patches.
3) The ST magnetometer driver had incorrect register addresses for the
   actual data channels.

----------------------------------------------------------------
Denis CIOCCA (1):
      iio:magnetometer: Bugfix magnetometer default output registers

Lars-Peter Clausen (2):
      iio: Add reference counting for buffers
      iio: Remove debugfs entries in iio_device_unregister()

Sachin Kamat (1):
      iio: amplifiers: ad8366: Remove regulator_put

 drivers/iio/amplifiers/ad8366.c                 |  4 +--
 drivers/iio/buffer_cb.c                         | 21 +++++++----
 drivers/iio/industrialio-buffer.c               | 41 +++++++++++++++++++---
 drivers/iio/industrialio-core.c                 |  6 +++-
 drivers/iio/industrialio-triggered-buffer.c     |  7 ++--
 drivers/iio/kfifo_buf.c                         |  8 ++++-
 drivers/iio/magnetometer/st_magn_core.c         | 18 +++++-----
 drivers/staging/iio/accel/lis3l02dq_ring.c      |  2 +-
 drivers/staging/iio/accel/sca3000_ring.c        | 13 ++++---
 drivers/staging/iio/iio_simple_dummy_buffer.c   |  2 +-
 drivers/staging/iio/impedance-analyzer/ad5933.c |  8 +++--
 drivers/staging/iio/meter/ade7758_ring.c        |  7 ++--
 include/linux/iio/buffer.h                      | 46 +++++++++++++++++++++++++
 13 files changed, 146 insertions(+), 37 deletions(-)

Re: [PULL] IIO fixes for 3.12 set 2

[Greg KH]

On Sun, Sep 29, 2013 at 09:56:39PM +0100, Jonathan Cameron wrote:
> The following changes since commit bda2f8fca20b564ac8edb2b9c080d942c2144359:
> 
>   iio:buffer_cb: Add missing iio_buffer_init() (2013-09-21 12:52:50 +0100)
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git tags/iio-fixes-for-3.12b

Let me wait for 3.12-rc3 to be out before pulling this, I just sent a
pull request to Linus a few minutes ago...

thanks,

greg k-h

Re: [PULL] IIO fixes for 3.12 set 2

[Greg KH]

On Sun, Sep 29, 2013 at 09:56:39PM +0100, Jonathan Cameron wrote:
> The following changes since commit bda2f8fca20b564ac8edb2b9c080d942c2144359:
> 
>   iio:buffer_cb: Add missing iio_buffer_init() (2013-09-21 12:52:50 +0100)
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git tags/iio-fixes-for-3.12b
> 
> for you to fetch changes up to f09b44ed1d8553c8a91b8de8cfa05f2ea585ab0d:
> 
>   iio:magnetometer: Bugfix magnetometer default output registers (2013-09-28 12:03:24 +0100)
> 
> ----------------------------------------------------------------
> Second set of IIO fixes for the 3.12 cycle.
> 
> One large fix here to add reference counting to IIO's buffers
> in order to prevent them being prematurely freed. The actual code addition
> is small but needs to be repeated in a number of different places.

That's a pretty major change to be doing so late in the development
cycle.  Are you _sure_ it's needed right now?

A few comments on the patch itself:

+static inline void iio_buffer_get(struct iio_buffer *buffer)
+{
+       kref_get(&buffer->ref);
+}

Traditionally a "get" function allows NULL pointers, and returns a
pointer to the object.  So that would mean this would look like:

static inline struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer)
{
	if (buffer)
		kref_get(&buffer->ref);
	return buffer;
}

Why does it need to be inline?

With that change, your iio_device_attach_buffer() call becomes one line:
	indio_dev->buffer = iio_buffer_get(buffer);


Anyway, this is a really major change, and not anything that I can
defend so late in the development cycle.  Why are you making it now?
What happened that requires it at this point in time?

Oh, you forgot to include an "empty" function for iio_buffer_get() if
CONFIG_IIO_BUFFER is not defined (matching the other 2 you did provide.)

Why export __iio_buffer_release?  Why not just make these "real"
functions, then there is no need to use a __ function, or export it.

The three other patches here look fine to me, I can take them, but not
this one at this point in time, unless you have a lot more justification
for it.

thanks,

greg k-h

Re: [PULL] IIO fixes for 3.12 set 2

[Jonathan Cameron]

Greg KH <gregkh@linuxfoundation.org> wrote:
>On Sun, Sep 29, 2013 at 09:56:39PM +0100, Jonathan Cameron wrote:
>> The following changes since commit
>bda2f8fca20b564ac8edb2b9c080d942c2144359:
>> 
>>   iio:buffer_cb: Add missing iio_buffer_init() (2013-09-21 12:52:50
>+0100)
>> 
>> are available in the git repository at:
>> 
>>   git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git
>tags/iio-fixes-for-3.12b
>> 
>> for you to fetch changes up to
>f09b44ed1d8553c8a91b8de8cfa05f2ea585ab0d:
>> 
>>   iio:magnetometer: Bugfix magnetometer default output registers
>(2013-09-28 12:03:24 +0100)
>> 
>> ----------------------------------------------------------------
>> Second set of IIO fixes for the 3.12 cycle.
>> 
>> One large fix here to add reference counting to IIO's buffers
>> in order to prevent them being prematurely freed. The actual code
>addition
>> is small but needs to be repeated in a number of different places.
>
>That's a pretty major change to be doing so late in the development
>cycle.  Are you _sure_ it's needed right now?
No more than it has been needed for a couple of years. I guess it can wait a little longer! I think it is more likely to be hit with USB devices now present though but they have been about for a while as well.


>
>A few comments on the patch itself:
>
>+static inline void iio_buffer_get(struct iio_buffer *buffer)
>+{
>+       kref_get(&buffer->ref);
>+}
>
>Traditionally a "get" function allows NULL pointers, and returns a
>pointer to the object.  So that would mean this would look like:
>
>static inline struct iio_buffer *iio_buffer_get(struct iio_buffer
>*buffer)
>{
>	if (buffer)
>		kref_get(&buffer->ref);
>	return buffer;
>}
>
>Why does it need to be inline?
>
>With that change, your iio_device_attach_buffer() call becomes one
>line:
>	indio_dev->buffer = iio_buffer_get(buffer);
>
>
>Anyway, this is a really major change, and not anything that I can
>defend so late in the development cycle.  Why are you making it now?

Purely on the basis that a fix should go in ASAP.  I did wonder if should hold this for next. Clearly the answer was yes on that front!  Thanks as ever for restraining my worst excesses.

>What happened that requires it at this point in time?
Nothing changed. This has been there from the start. I didn't think this aspect through properly and it has taken this long for anyone to notice.

>
>Oh, you forgot to include an "empty" function for iio_buffer_get() if
>CONFIG_IIO_BUFFER is not defined (matching the other 2 you did
>provide.)
>
>Why export __iio_buffer_release?  Why not just make these "real"
>functions, then there is no need to use a __ function, or export it.
>
>The three other patches here look fine to me, I can take them, but not
>this one at this point in time, unless you have a lot more
>justification
>for it.
Sorry about this. I am still learning where to set the boundary for fixes. Thanks for taking such a close look!

Lars, can you refresh and repost to go in next merge cycle.

There are a few more related patches but they don't effect any current mainline drivers so were always going to be next material.

I will drop this patch and send a pull request for the others in that branch later today or tomorrow.

Jonathan
>
>thanks,
>
>greg k-h

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