[PATCH] I2C: OMAP: xfer: fix runtime PM get/put balance on error

[Shubhrajyoti Datta]

Hi Kevin,
Thanks for the patch ,
a doubt below

On Wed, Jun 27, 2012 at 7:15 AM, Kevin Hilman <khilman at ti.com> wrote:
> In omap_i2c_xfer(), ensure pm_runtime_put() is called, even on
> failure.
So the failure means that the usecount is incremented. However the
device was not
enabled. In that case could we consider

   void pm_runtime_put_noidle(struct device *dev);
    - decrement the device's usage counter

Which will only decrement the counter and does not try to disable it.

However I am not sure what happens if you try to disable an already
disabled device.

>
> Without this, after a failed xfer, the runtime PM usecount will have
> been incremented, but not decremented

Agree.

> causing the usecount to never
> reach zero after a failure.  This keeps the device always runtime PM
> enabled which keeps the enclosing power domain active, and prevents
> full-chip retention/off from happening during idle.
>
> Cc: Shubhrajyoti D <shubhrajyoti at ti.com>
> Signed-off-by: Kevin Hilman <khilman at ti.com>
> ---
> This patch applies to current i2c-embedded/for-next branch
>
>  drivers/i2c/busses/i2c-omap.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 9895fa7..b105733 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -582,7 +582,7 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
>
>        r = pm_runtime_get_sync(dev->dev);
>        if (IS_ERR_VALUE(r))
> -               return r;
> +               goto out;
>
>        r = omap_i2c_wait_for_bb(dev);
>        if (r < 0)
> --
> 1.7.9.2
>
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