Commit 0a50f61c authored by Todd Poynor's avatar Todd Poynor Committed by Greg Kroah-Hartman
Browse files

drivers: base: initcall_debug logs for driver probe times 



Add initcall_debug logs for each driver device probe call, for example:

   probe of a3800000.ramoops returned 1 after 3007 usecs

This replaces the previous code added to report times for deferred
probes.  It also reports OF platform bus device creates that were
formerly lumped together in a single entry for function
of_platform_default_populate_init, as well as helping to annotate other
initcalls that involve device probing.

Remove restriction on printing probe times only during initcalls, since
initcall_debug now continues to show driver timing info past the boot
phase.

Signed-off-by: default avatarTodd Poynor <toddpoynor@google.com>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7daf201d

drivers/base/dd.c

+22 −28
Original line number Diff line number Diff line
@@ -53,7 +53,6 @@ static DEFINE_MUTEX(deferred_probe_mutex); 
static LIST_HEAD(deferred_probe_pending_list);

static LIST_HEAD(deferred_probe_active_list);

static atomic_t deferred_trigger_count = ATOMIC_INIT(0);

static bool initcalls_done;



/*

 * In some cases, like suspend to RAM or hibernation, It might be reasonable
@@ -62,26 +61,6 @@ static bool initcalls_done; 
 */

static bool defer_all_probes;



/*

 * For initcall_debug, show the deferred probes executed in late_initcall

 * processing.

 */

static void deferred_probe_debug(struct device *dev)

{

	ktime_t calltime, delta, rettime;

	unsigned long long duration;



	printk(KERN_DEBUG "deferred probe %s @ %i\n", dev_name(dev),

	       task_pid_nr(current));

	calltime = ktime_get();

	bus_probe_device(dev);

	rettime = ktime_get();

	delta = ktime_sub(rettime, calltime);

	duration = (unsigned long long) ktime_to_ns(delta) >> 10;

	printk(KERN_DEBUG "deferred probe %s returned after %lld usecs\n",

	       dev_name(dev), duration);

}



/*

 * deferred_probe_work_func() - Retry probing devices in the active list.

 */
@@ -125,11 +104,7 @@ static void deferred_probe_work_func(struct work_struct *work) 
		device_pm_move_to_tail(dev);



		dev_dbg(dev, "Retrying from deferred list\n");

		if (initcall_debug && !initcalls_done)

			deferred_probe_debug(dev);

		else

		bus_probe_device(dev);



		mutex_lock(&deferred_probe_mutex);



		put_device(dev);
@@ -237,7 +212,6 @@ static int deferred_probe_initcall(void) 
	driver_deferred_probe_trigger();

	/* Sort as many dependencies as possible before exiting initcalls */

	flush_work(&deferred_probe_work);

	initcalls_done = true;

	return 0;

}

late_initcall(deferred_probe_initcall);
@@ -527,6 +501,23 @@ done: 
	return ret;

}



/*

 * For initcall_debug, show the driver probe time.

 */

static int really_probe_debug(struct device *dev, struct device_driver *drv)

{

	ktime_t calltime, delta, rettime;

	int ret;



	calltime = ktime_get();

	ret = really_probe(dev, drv);

	rettime = ktime_get();

	delta = ktime_sub(rettime, calltime);

	printk(KERN_DEBUG "probe of %s returned %d after %lld usecs\n",

	       dev_name(dev), ret, (s64) ktime_to_us(delta));

	return ret;

}



/**

 * driver_probe_done

 * Determine if the probe sequence is finished or not.
@@ -585,6 +576,9 @@ int driver_probe_device(struct device_driver *drv, struct device *dev) 
		pm_runtime_get_sync(dev->parent);



	pm_runtime_barrier(dev);

	if (initcall_debug)

		ret = really_probe_debug(dev, drv);

	else

		ret = really_probe(dev, drv);

	pm_request_idle(dev);

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