Re: [PATCH 04/10] driver core: Don't return EPROBE_DEFER to userspace during sysfs bind

[Alex Williamson <alex.williamson@redhat.com>]

On Tue, 15 Jun 2021 15:35:13 +0200
Christoph Hellwig <hch@lst.de> wrote:

> @@ -547,10 +538,9 @@ static int call_driver_probe(struct device *dev, struct device_driver *drv)
>  
>  static int really_probe(struct device *dev, struct device_driver *drv)
>  {
> -	int local_trigger_count = atomic_read(&deferred_trigger_count);
>  	bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) &&
>  			   !drv->suppress_bind_attrs;
> -	int ret = -EPROBE_DEFER, probe_ret = 0;
> +	int ret, probe_ret = 0;

nit, probe_ret initialization could be removed with this patch too.

>  
>  	if (defer_all_probes) {
>  		/*
> @@ -559,17 +549,13 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>  		 * wait_for_device_probe() right after that to avoid any races.
>  		 */
>  		dev_dbg(dev, "Driver %s force probe deferral\n", drv->name);
> -		driver_deferred_probe_add(dev);
> -		return ret;
> +		return -EPROBE_DEFER;
>  	}
>  
>  	ret = device_links_check_suppliers(dev);
> -	if (ret == -EPROBE_DEFER)
> -		driver_deferred_probe_add_trigger(dev, local_trigger_count);
>  	if (ret)
>  		return ret;
>  
> -	atomic_inc(&probe_count);
>  	pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
>  		 drv->bus->name, __func__, drv->name, dev_name(dev));
>  	if (!list_empty(&dev->devres_head)) {
> @@ -681,11 +667,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>  		dev->pm_domain->dismiss(dev);
>  	pm_runtime_reinit(dev);
>  	dev_pm_set_driver_flags(dev, 0);
> -	if (probe_ret == -EPROBE_DEFER)
> -		driver_deferred_probe_add_trigger(dev, local_trigger_count);

This was the only possible uninitialized use case afaict.  Thanks,

Alex