dwc3_qcom_of_register_core() uses of_platform_populate() to add the dwc3 core device. The driver core will try to probe the device, however this might fail (e.g. due to deferred probing) and of_platform_populate() would still return 0 if the device was successully added to the platform bus. Verify that the core device is actually bound to its driver before using it, defer probing of the dwc3_qcom device if the core device isn't ready (yet). Fixes: a4333c3a6ba9 ("usb: dwc3: Add Qualcomm DWC3 glue driver"). Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx> --- depends on: https://lore.kernel.org/patchwork/patch/1251661/ ("driver core:Export the symbol device_is_bound") drivers/usb/dwc3/dwc3-qcom.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c index 1dfd024cd06b..5a9036b050c6 100644 --- a/drivers/usb/dwc3/dwc3-qcom.c +++ b/drivers/usb/dwc3/dwc3-qcom.c @@ -537,6 +537,16 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev) return -ENODEV; } + /* + * A successful return from of_platform_populate() only guarantees that + * the core device was added to the platform bus, however it might not + * be bound to its driver (e.g. due to deferred probing). This driver + * requires the core device to be fully initialized, so defer probing + * if it isn't ready (yet). + */ + if (!device_is_bound(&qcom->dwc3->dev)) + return -EPROBE_DEFER; + return 0; } -- 2.27.0.290.gba653c62da-goog