Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 12 Apr 2024 09:41:19 +0200 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH v3 2/2] PCI: of: Attach created of_node to existing device |
| |
On Thu, Apr 11, 2024 at 03:34:49PM -0500, Rob Herring wrote: > On Thu, Apr 11, 2024 at 03:23:55PM +0200, Greg Kroah-Hartman wrote: > > On Mon, Mar 25, 2024 at 04:39:15PM +0100, Herve Codina wrote: > > > The commit 407d1a51921e ("PCI: Create device tree node for bridge") > > > creates of_node for PCI devices. > > > > > > During the insertion handling of these new DT nodes done by of_platform, > > > new devices (struct device) are created. For each PCI devices a struct > > > device is already present (created and handled by the PCI core). > > > Having a second struct device to represent the exact same PCI device is > > > not correct. > > > > > > On the of_node creation: > > > - tell the of_platform that there is no need to create a device for this > > > node (OF_POPULATED flag), > > > - link this newly created of_node to the already present device, > > > - tell fwnode that the device attached to this of_node is ready using > > > fwnode_dev_initialized(). > > > > > > With this fix, the of_node are available in the sysfs device tree: > > > /sys/devices/platform/soc/d0070000.pcie/ > > > + of_node -> .../devicetree/base/soc/pcie@d0070000 > > > + pci0000:00 > > > + 0000:00:00.0 > > > + of_node -> .../devicetree/base/soc/pcie@d0070000/pci@0,0 > > > + 0000:01:00.0 > > > + of_node -> .../devicetree/base/soc/pcie@d0070000/pci@0,0/dev@0,0 > > > > > > On the of_node removal, revert the operations. > > > > > > Fixes: 407d1a51921e ("PCI: Create device tree node for bridge") > > > Cc: stable@vger.kernel.org > > > Signed-off-by: Herve Codina <herve.codina@bootlin.com> > > > > I need an ack from the maintainer here before I can take this. > > Correct me if I'm wrong, but having the of_node sysfs link populated or > changed after device_add is a race we lost. Userspace is notified about > the new device and then some time later the symlink shows up.
Ah, yes, I missed that, good catch, this will not work.
> However, it so far is not appearing that there's an easy way to > reshuffle order of things to fix this. > > Maybe the short term (and stable) answer just don't create any of_node > symlinks on these dynamically created nodes.
That would work, but does userspace really need to know this information?
thanks,
greg k-h
| ![\](/images/icornerr.gif) |