On Tue, Jun 19, 2018 at 11:59 PM, Javier Martinez Canillas <[email protected]> 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 >
FWIW, Reviewed-by: Andy Shevchenko <[email protected]> > Signed-off-by: Javier Martinez Canillas <[email protected]> > > --- > > Changes since RFC v1: > - Remove unneeded ret variable from deferred_devs_show() > > Changes since RFC v2: > - Use DEFINE_SHOW_ATTRIBUTE() macro. > - Don't propagate debugfs_create_file() error. > - Remove IS_ENABLED(CONFIG_DEBUG_FS) guards. > - Drop RFC prefix. > > drivers/base/dd.c | 22 ++++++++++++++++++++++ > 1 file changed, 22 insertions(+) > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index 1435d7281c6..8ec9e3cfbe4 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -16,6 +16,7 @@ > * Copyright (c) 2007-2009 Novell Inc. > */ > > +#include <linux/debugfs.h> > #include <linux/device.h> > #include <linux/delay.h> > #include <linux/dma-mapping.h> > @@ -224,6 +225,24 @@ void device_unblock_probing(void) > driver_deferred_probe_trigger(); > } > > +/* > + * 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; > +} > +DEFINE_SHOW_ATTRIBUTE(deferred_devs); > + > /** > * deferred_probe_initcall() - Enable probing of deferred devices > * > @@ -233,6 +252,9 @@ void device_unblock_probing(void) > */ > static int deferred_probe_initcall(void) > { > + debugfs_create_file("deferred_devices", 0444, NULL, NULL, > + &deferred_devs_fops); > + > 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
