On Tue, Jun 19, 2018 at 9:33 PM, Javier Martinez Canillas
<javi...@redhat.com> wrote:
> For debugging purposes it may be useful to know what are the devices whose
> probe function was deferred. Add a debugfs entry showing that information.
>
> $ cat /sys/kernel/debug/deferred_devices
> 48070000.i2c:twl@48:bci
> musb-hdrc.0.auto
> omapdrm.0
> +#if IS_ENABLED(CONFIG_DEBUG_FS)
> +#include <linux/debugfs.h>
> +
> +static struct dentry *deferred_devices;
> +
> +/*
> + * deferred_devs_show() - Show the devices in the deferred probe pending
> list.
> + */
> +static int deferred_devs_show(struct seq_file *s, void *data)
> +{
> + struct device_private *curr;
> +
> + mutex_lock(&deferred_probe_mutex);
> +
> + list_for_each_entry(curr, &deferred_probe_pending_list,
> deferred_probe)
> + seq_printf(s, "%s\n", dev_name(curr->device));
> +
> + mutex_unlock(&deferred_probe_mutex);
> +
> + return 0;
> +}
> +
> +static int deferred_devs_open(struct inode *inode, struct file *file)
> +{
> + return single_open(file, deferred_devs_show, inode->i_private);
> +}
> +
> +static const struct file_operations deferred_devs_fops = {
> + .owner = THIS_MODULE,
> + .open = deferred_devs_open,
> + .read = seq_read,
> + .llseek = seq_lseek,
> + .release = single_release,
> +};
Isn't this DEFINE_SHOW_ATTRIBUTE() ?
> +#endif /* IS_ENABLED(CONFIG_DEBUG_FS) */
> +
> /**
> * deferred_probe_initcall() - Enable probing of deferred devices
> *
> @@ -233,6 +269,14 @@ void device_unblock_probing(void)
> */
> static int deferred_probe_initcall(void)
> {
> + if (IS_ENABLED(CONFIG_DEBUG_FS)) {
> + deferred_devices = debugfs_create_file("deferred_devices",
> + 0444, NULL, NULL,
> + &deferred_devs_fops);
> + if (!deferred_devices)
> + return -ENOMEM;
> + }
> +
> driver_deferred_probe_enable = true;
> driver_deferred_probe_trigger();
> /* Sort as many dependencies as possible before exiting initcalls */
> --
> 2.17.1
>
--
With Best Regards,
Andy Shevchenko
