Sometimes, more than one (generally two) device can point to the same
fwnode. However, only one device is set as the fwnode's device
(fwnode->dev) and can be looked up from the fwnode.
Typically, only one of these devices actually have a driver and actually
probe. If we create device links for all these devices, then the
suppliers' of these devices (with the same fwnode) will never get a
sync_state() call because one of their consumer devices will never probe
(because they don't have a driver).
So, create device links only for the device that is considered as the
fwnode's device.
One such example of this is the PCI bridge platform_device and the
corresponding pci_bus device. Both these devices will have the same
fwnode. It's the platform_device that is registered first and is set as
the fwnode's device. Also the platform_device is the one that actually
probes. Without this patch none of the suppliers of a PCI bridge
platform_device would get a sync_state() callback.
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200321045448.15192-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 4dbe191c046e71d6ea1ba85365ecb33961b07c4f)
[fixed minor conflict due to missing fw_devlink_flags]
Bug: 151891594
Change-Id: Ife526b52d1e25c420d07dcf46ed466dc80f7f5eb
Signed-off-by: Saravana Kannan <saravanak@google.com>
efd676d50a