From: Alexis Lothoré alexis.lothore@bootlin.com
mainline inclusion from mainline-v6.3 commit dc70eb868b9cd2ca01313e5a394e6ea001d513e9 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/?i...
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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 0d70af3c2530 ("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: 0d70af3c2530 ("fpga: bridge: Use standard dev_release for class driver") Signed-off-by: Alexis Lothoré alexis.lothore@bootlin.com Acked-by: Xu Yilun yilun.xu@intel.com Link: https://lore.kernel.org/r/20230404133102.2837535-2-alexis.lothore@bootlin.co... Signed-off-by: Xu Yilun yilun.xu@intel.com Signed-off-by: Ma Wupeng mawupeng1@huawei.com --- drivers/fpga/fpga-bridge.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c index 1a7ca0489d91..27750b18803a 100644 --- a/drivers/fpga/fpga-bridge.c +++ b/drivers/fpga/fpga-bridge.c @@ -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: