Hi,
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).
Creating a new device from a DT node leads to some kind of wrong struct
device duplication to represent the exact same PCI device.
This patch series first introduces device_{add,remove}_of_node() in
order to add or remove a newly created of_node to an already existing
device.
Then it fixes the DT node creation for PCI devices to add or remove the
created node to the existing PCI device without any new device creation.
Best regards,
Hervé
Herve Codina (2):
driver core: Introduce device_{add,remove}_of_node()
PCI: of: Attach created of_node to existing device
drivers/base/core.c | 74 ++++++++++++++++++++++++++++++++++++++++++
drivers/pci/of.c | 15 +++++++--
include/linux/device.h | 2 ++
3 files changed, 89 insertions(+), 2 deletions(-)
--
2.42.0
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 and tell fwnode that the
device attached to this of_node is ready (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: [email protected]
Signed-off-by: Herve Codina <[email protected]>
---
drivers/pci/of.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 51e3dd0ea5ab..5afd2731e876 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -615,7 +615,8 @@ void of_pci_remove_node(struct pci_dev *pdev)
np = pci_device_to_OF_node(pdev);
if (!np || !of_node_check_flag(np, OF_DYNAMIC))
return;
- pdev->dev.of_node = NULL;
+
+ device_remove_of_node(&pdev->dev);
of_changeset_revert(np->data);
of_changeset_destroy(np->data);
@@ -668,12 +669,22 @@ void of_pci_make_dev_node(struct pci_dev *pdev)
if (ret)
goto out_free_node;
+ /*
+ * This of_node will be added to an existing device.
+ * Avoid any device creation and use the existing device
+ */
+ of_node_set_flag(np, OF_POPULATED);
+ np->fwnode.dev = &pdev->dev;
+ fwnode_dev_initialized(&np->fwnode, true);
+
ret = of_changeset_apply(cset);
if (ret)
goto out_free_node;
np->data = cset;
- pdev->dev.of_node = np;
+
+ /* Add the of_node to the existing device */
+ device_add_of_node(&pdev->dev, np);
kfree(name);
return;
--
2.42.0
On Thu, Nov 30, 2023 at 04:24:04PM +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 and tell fwnode that the
> device attached to this of_node is ready (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: [email protected]
How can this be cc: stable when the api it relies on is not?
confused,
greg k-h
Hi Greg,
On Thu, 30 Nov 2023 16:18:58 +0000
Greg Kroah-Hartman <[email protected]> wrote:
> On Thu, Nov 30, 2023 at 04:24:04PM +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 and tell fwnode that the
> > device attached to this of_node is ready (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: [email protected]
>
> How can this be cc: stable when the api it relies on is not?
>
> confused,
My bad, I will add cc: stable in the other patch needed.
Sorry about that.
Hervé
--
Hervé Codina, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com