Looks like I squashed/rebased a bit incorrectly. It's fixed in the
next patch in the series.
-Saravana
On Tue, Nov 5, 2019 at 2:29 PM Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote:
>
> On Monday, October 28, 2019 11:00:23 PM CET Saravana Kannan wrote:
> > Before this change, if a device is waiting on suppliers, it's assumed
> > that all those suppliers are needed for the device to probe
> > successfully. This change allows marking a devices as waiting only on
> > optional suppliers. This allows a device to wait on suppliers (and link
> > to them as soon as they are available) without preventing the device
> > from being probed.
> >
> > Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx>
> > ---
> > drivers/base/core.c | 28 +++++++++++++++++++++++++---
> > include/linux/device.h | 3 +++
> > 2 files changed, 28 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/base/core.c b/drivers/base/core.c
> > index 17ed054c4132..48cd43a91ce6 100644
> > --- a/drivers/base/core.c
> > +++ b/drivers/base/core.c
> > @@ -480,13 +480,25 @@ EXPORT_SYMBOL_GPL(device_link_add);
> > * This function is NOT meant to be called from the probe function of the
> > * consumer but rather from code that creates/adds the consumer device.
> > */
> > -static void device_link_wait_for_supplier(struct device *consumer)
> > +static void device_link_wait_for_supplier(struct device *consumer,
> > + bool need_for_probe)
> > {
> > mutex_lock(&wfs_lock);
> > list_add_tail(&consumer->links.needs_suppliers, &wait_for_suppliers);
> > + consumer->links.need_for_probe = need_for_probe;
> > mutex_unlock(&wfs_lock);
> > }
> >
> > +static void device_link_wait_for_mandatory_supplier(struct device *consumer)
> > +{
> > + device_link_wait_for_supplier(consumer, true);
> > +}
> > +
> > +static void device_link_wait_for_optional_supplier(struct device *consumer)
> > +{
> > + device_link_wait_for_supplier(consumer, false);
> > +}
> > +
> > /**
> > * device_link_add_missing_supplier_links - Add links from consumer devices to
> > * supplier devices, leaving any
> > @@ -656,7 +668,8 @@ int device_links_check_suppliers(struct device *dev)
> > * probe.
> > */
> > mutex_lock(&wfs_lock);
> > - if (!list_empty(&dev->links.needs_suppliers)) {
> > + if (!list_empty(&dev->links.needs_suppliers) &&
> > + dev->links.need_for_probe) {
> > mutex_unlock(&wfs_lock);
> > return -EPROBE_DEFER;
> > }
> > @@ -760,6 +773,15 @@ void device_links_driver_bound(struct device *dev)
> > {
> > struct device_link *link;
> >
> > + /*
> > + * If a device probes successfully, it's expected to have created all
> > + * the device links it needs to or make new device links as it needs
> > + * them. So, it no longer needs to wait on any suppliers.
> > + */
> > + mutex_lock(&wfs_lock);
> > + list_del_init(&dev->links.needs_suppliers);
> > + mutex_unlock(&wfs_lock);
> > +
> > device_links_write_lock();
> >
> > list_for_each_entry(link, &dev->links.consumers, s_node) {
> > @@ -2393,7 +2415,7 @@ int device_add(struct device *dev)
> >
> > if (fwnode_has_op(dev->fwnode, add_links)
> > && fwnode_call_int_op(dev->fwnode, add_links, dev))
> > - device_link_wait_for_supplier(dev);
> > + device_link_wait_for_mandatory_supplier(dev, true);
>
> Does this compile even?
>
> The function takes one argument according to the definition above ...
>
> > bus_probe_device(dev);
> > if (parent)
> > diff --git a/include/linux/device.h b/include/linux/device.h
> > index f1f2aa0b19da..4fd33da9a848 100644
> > --- a/include/linux/device.h
> > +++ b/include/linux/device.h
> > @@ -1156,6 +1156,8 @@ enum dl_dev_state {
> > * @consumers: List of links to consumer devices.
> > * @needs_suppliers: Hook to global list of devices waiting for suppliers.
> > * @defer_sync: Hook to global list of devices that have deferred sync_state.
> > + * @need_for_probe: If needs_suppliers is on a list, this indicates if the
> > + * suppliers are needed for probe or not.
> > * @status: Driver status information.
> > */
> > struct dev_links_info {
> > @@ -1163,6 +1165,7 @@ struct dev_links_info {
> > struct list_head consumers;
> > struct list_head needs_suppliers;
> > struct list_head defer_sync;
> > + bool need_for_probe;
> > enum dl_dev_state status;
> > };
> >
> >
>
>
>
>
