[i2c] i2c-remove-redundant-i2c_client-list.patch

[Jean Delvare]

Hi David,

On Mon, 14 Jan 2008 14:20:48 -0800, David Brownell wrote:
> OK, here's the trimmed-down patch that leaves the deletion
> paths untouched until we have a better solution.  I've only
> build-tested it, but it's basically $SUBJECT without those
> troublesome paths.
> 
> - Dave
> 
> =======	CUT HERE
> The i2c_adapter.clients list of i2c_client nodes duplicates driver
> model state.  This patch starts removing that list, letting us remove
> most existing users of those i2c-core lists.
> 
>  * The core I2C code now iterates over the driver model's list instead
>    of the i2c-internal one in some places where it's safe:
>       - Passing a command/ioctl to each client, a mechanims
>         used almost exclusively by DVB adapters;
>       - Device address checking, in both i2c-core and i2c-dev.
> 
>  * Provide i2c_verify_client() to use with driver model iterators.
> 
>  * Flag the relevant i2c_adapter and i2c_client fields as deprecated,
>    to help prevent new users from appearing.
> 
> For the moment the list needs to stick around, since some issues show
> up when deleting devices created by legacy I2C drivers.  (They don't
> follow standard driver model rules.  Removing those devices can cause
> self-deadlocks.)
> 
> Signed-off-by: David Brownell <dbrownell at users.sourceforge.net>
> ---
>  drivers/i2c/i2c-core.c |   78 ++++++++++++++++++++++++++++---------------------
>  drivers/i2c/i2c-dev.c  |   29 +++++++-----------
>  include/linux/i2c.h    |    8 +++--
>  3 files changed, 63 insertions(+), 52 deletions(-)

Looks good to me, I've applied that. I was about to suggest possible
improvements with regards to locking scope but I see that you have
already submitted an incremental patch so I'll review it first.

I've given some testing to this patch and I didn't see any problem.

Thanks,
-- 
Jean Delvare