[PATCH] dma-buf/reservation: Wrap ww_mutex_trylock

[Joonas Lahtinen]

On ti, 2017-02-21 at 09:30 +0000, Chris Wilson wrote:
> In a similar fashion to reservation_object_lock() and
> reservation_object_unlock(), ww_mutex_trylock is also useful and so is
> worth wrapping for consistency.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Sumit Semwal <sumit.semwal at linaro.org>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>

<SNIP>

> @@ -151,6 +151,26 @@ reservation_object_lock(struct reservation_object *obj,
>  }
>  
>  /**
> + * reservation_object_trylock - trylock the reservation object
> + * @obj: the reservation object
> + *
> + * Tries to lock the reservation object for exclusive access and modification.
> + * Note, that the lock is only against other writers, readers will run
> + * concurrently with a writer under RCU. The seqlock is used to notify readers
> + * if they overlap with a writer.
> + *
> + * Also note that since no context is provided, no deadlock protection is
> + * possible.
> + *
> + * Returns true if the lock was acquired, false otherwise.
> + */
> +static inline bool

I'd carry over the __must_check flag, with that;

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

Regards, Joonas

> +reservation_object_trylock(struct reservation_object *obj)
> +{
> +	return ww_mutex_trylock(&obj->lock);
> +}
> +
> +/**
>   * reservation_object_unlock - unlock the reservation object
>   * @obj: the reservation object
>   *
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation