Messages in this thread Patch in this message | | | From | Krishna Kurapati <> | Subject | [PATCH v2] usb: dwc3: qcom: Defer dwc3-qcom probe if dwc3 isn't probed properly | Date | Fri, 15 Jul 2022 18:51:52 +0530 |
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On SC7180 devices, it is observed that dwc3 probing is deferred because device_links_check_suppliers() finds that '88e3000.phy' isn't ready yet.
As a part of its probe call, dwc3-qcom driver checks if dwc3 core is wakeup capable or not. If the dwc3 core is wakeup capable, driver configures dwc-qcom's power domain to be always ON. Also it configures dp/dm interrupts accordingly to support wakeup from system suspend.
More info regarding the same can be found at: commit d9be8d5c5b03 ("usb: dwc3: qcom: Keep power domain on to retain controller status") commit 6895ea55c385 ("usb: dwc3: qcom: Configure wakeup interrupts during suspend")
In the event, dwc3 probe gets deferred and is processed after dwc3-qcom probe, driver ends up reading the wakeup capability of dwc3 core as false leading to instability in suspend/resume path.
To avoid this scenario, ensure dwc3_probe is successful by checking if appropriate driver is assigned to it or not after the of_platform_populate call. If it isn't then defer dwc3-qcom probe as well.
Fixes: 649f5c842ba3 ("usb: dwc3: core: Host wake up support from system suspend") Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com> --- v2: Set return value to EPROBE_DEFER to drop reference to dwc3 node
drivers/usb/dwc3/dwc3-qcom.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c index 7703655..6676b39 100644 --- a/drivers/usb/dwc3/dwc3-qcom.c +++ b/drivers/usb/dwc3/dwc3-qcom.c @@ -722,6 +722,9 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev) dev_err(dev, "failed to get dwc3 platform device\n"); } + if (!qcom->dwc3->dev.driver) + ret = -EPROBE_DEFER; + node_put: of_node_put(dwc3_np); -- 2.7.4
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