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[drivers] Fix OFW bus conflict and prevent duplicate device creation #11090

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[drivers] Fix OFW bus conflict and prevent duplicate device creation #11090

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19 changes: 9 additions & 10 deletions components/drivers/core/platform_ofw.c
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@
* Change Logs:
* Date Author Notes
* 2023-06-04 GuEe-GUI the first version
* 2025-12-25 lhxj fix OFW bus conflict and prevent duplicate device creation
*/

#include <rtthread.h>
Expand Down Expand Up @@ -223,16 +224,14 @@ rt_err_t rt_platform_ofw_request(struct rt_ofw_node *np)

if (dev)
{
/* Was create */
if (dev->drv)
{
/* Was probe OK */
err = RT_EOK;
}
else
{
err = rt_bus_reload_driver_device(dev->bus, dev);
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@GuEe-GUI GuEe-GUI Dec 29, 2025

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这里的目的是为了舍弃之前匹配上的驱动，重新根据设备状态进行驱动匹配，看上去并没有影响 I2C/SPI 呀，如果会发生错误，那应该是调用方的方法不对。

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@lhxj lhxj Jan 10, 2026 •
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查阅 rt_bus_reload_driver_device 的底层实现，发现内核断言严格禁止了这种操作。说明这个函数本身是为了“跨总线迁移”设计的，不支持“同总线重载”。
image

  1. API 的限制：在 rt_bus_reload_driver_device 函数内部，存在如下断言： RT_ASSERT(dev->bus != new_bus); 当前代码执行 rt_bus_reload_driver_device(dev->bus, dev) 时，将当前总线作为新总线传入。这会直接触发断言失败，程序根本没机会执行后续的匹配逻辑。
  2. 之前的初始化时序可能使得 pinctrl 驱动在被请求前就已经加载完成了。此时 dev->drv 不为空，代码走了 if 分支，从而避开了这个有 Bug 的 else 分支。
image image
  1. 而当在任何时序稍有变动的场景中，若pinctrl 被请求时驱动尚未加载 (drv == NULL)。代码则会掉入 else 分支并触发崩溃。

}
/*
* Device was already created (np->dev != NULL).
* - If it's already probed (dev->drv != NULL), nothing to do.
* - If not yet probed (dev->drv == NULL), it belongs to its native bus
* (e.g. I2C/SPI) which will handle probing; platform bus should not reload
* or transfer it, to avoid cross-bus conflicts.
*/
err = RT_EOK;
}
else
{
Expand Down
4 changes: 4 additions & 0 deletions components/drivers/i2c/dev_i2c_bus.c
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@
* Change Logs:
* Date Author Notes
* 2022-12-06 GuEe-GUI first version
* 2025-12-25 lhxj mark OFW node as taken to prevent platform bus duplication
*/

#include <rtdevice.h>
Expand Down Expand Up @@ -63,6 +64,9 @@ void i2c_bus_scan_clients(struct rt_i2c_bus_device *bus)

rt_dm_dev_set_name(&client->parent, "%s", client->name);

/* Mark this OFW node as taken to prevent platform bus from creating duplicate device */
i2c_client_np->dev = &client->parent;

rt_i2c_device_register(client);

if (i2c_client_np != child_np)
Expand Down
6 changes: 5 additions & 1 deletion components/drivers/spi/dev_spi_bus.c
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@
* Change Logs:
* Date Author Notes
* 2022-12-06 GuEe-GUI first version
* 2025-12-25 lhxj mark OFW node as taken to prevent platform bus duplication; fix cppcheck warning
*/

#include "dev_spi_dm.h"
Expand Down Expand Up @@ -69,6 +70,9 @@ void spi_bus_scan_devices(struct rt_spi_bus *bus)
continue;
}

/* Mark this OFW node as taken to prevent platform bus from creating duplicate device */
spi_dev_np->dev = &spi_dev->parent;

rt_spi_device_register(spi_dev);
}
}
Expand Down Expand Up @@ -163,7 +167,7 @@ static rt_err_t spi_probe(rt_device_t dev)
rt_spidev_device_init(device, rt_dm_dev_get_name(&device->parent));
}

return err;
return RT_EOK;
}

static rt_err_t spi_remove(rt_device_t dev)
Expand Down