Commit 27e09cfe authored by Alexis Lothoré's avatar Alexis Lothoré Committed by Wupeng Ma
Browse files

fpga: bridge: properly initialize bridge device before populating children 

mainline inclusion
from mainline-v6.3
commit dc70eb86
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA7YMH

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dc70eb868b9cd2ca01313e5a394e6ea001d513e9



--------------------------------

The current code path can lead to warnings because of uninitialized device,
which contains, as a consequence, uninitialized kobject. The uninitialized
device is passed to of_platform_populate, which will at some point, while
creating child device, try to get a reference on uninitialized parent,
resulting in the following warning:

kobject: '(null)' ((ptrval)): is not initialized, yet kobject_get() is
being called.

The warning is observed after migrating a kernel 5.10.x to 6.1.x.
Reverting commit 0d70af3c ("fpga: bridge: Use standard dev_release for
class driver") seems to remove the warning.
This commit aggregates device_initialize() and device_add() into
device_register() but this new call is done AFTER of_platform_populate

Fixes: 0d70af3c ("fpga: bridge: Use standard dev_release for class driver")
Signed-off-by: default avatarAlexis Lothoré <alexis.lothore@bootlin.com>
Acked-by: default avatarXu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20230404133102.2837535-2-alexis.lothore@bootlin.com


Signed-off-by: default avatarXu Yilun <yilun.xu@intel.com>
Signed-off-by: default avatarMa Wupeng <mawupeng1@huawei.com>
parent d2b3be80

drivers/fpga/fpga-bridge.c

+2 −1
Original line number Diff line number Diff line
@@ -360,7 +360,6 @@ fpga_bridge_register(struct device *parent, const char *name, 
	bridge->dev.parent = parent;

	bridge->dev.of_node = parent->of_node;

	bridge->dev.id = id;

	of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);



	ret = dev_set_name(&bridge->dev, "br%d", id);

	if (ret)
@@ -372,6 +371,8 @@ fpga_bridge_register(struct device *parent, const char *name, 
		return ERR_PTR(ret);

	}



	of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);



	return bridge;



error_device: