Re: [PATCH] clockevents: Introduce mode specific callbacks

From: Peter Zijlstra
Date: Tue Feb 10 2015 - 09:15:52 EST


On Wed, Feb 04, 2015 at 01:06:23PM +0530, Viresh Kumar wrote:
> + /*
> + * Mode transition callback(s): Only one of the two groups should be
> + * defined:
> + * - set_mode(), only for modes <= CLOCK_EVT_MODE_RESUME.
> + * - set_mode_{shutdown|periodic|oneshot|resume}().
> + */
> void (*set_mode)(enum clock_event_mode mode,
> struct clock_event_device *);
> + int (*set_mode_periodic)(struct clock_event_device *);
> + int (*set_mode_oneshot)(struct clock_event_device *);
> + int (*set_mode_shutdown)(struct clock_event_device *);
> + int (*set_mode_resume)(struct clock_event_device *);




> +/* Sanity check of mode transition callbacks */
> +static int clockevents_sanity_check(struct clock_event_device *dev)
> +{
> + /* Legacy set_mode() callback */
> + if (dev->set_mode)
> + return 0;
> +
> + if (dev->features & CLOCK_EVT_FEAT_DUMMY)
> + return 0;
> +
> + /* New mode-specific callbacks */
> + if (!dev->set_mode_shutdown)
> + return -EINVAL;
> +
> + if ((dev->features & CLOCK_EVT_FEAT_PERIODIC) &&
> + !dev->set_mode_periodic)
> + return -EINVAL;
> +
> + if ((dev->features & CLOCK_EVT_FEAT_ONESHOT) &&
> + !dev->set_mode_oneshot)
> + return -EINVAL;
> +
> + return 0;
> +}

It appears to me you've not actually checked that condition outlined
above, a driver could set both the legacy and the new callbacks.


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