[PATCH] usb: dwc3: imx: avoid calling imx suspend/resume callbacks twice

[Xu Yang]

If a runtime suspend is executed followed by a system suspend, the driver
may invoke dwc3_imx_suspend() twice, which causes enable_irq() to be
called twice as well. This leads to an unbalanced IRQ state and may
trigger warnings or malfunction. Prevent this by checking the pm_suspended
flag before running the imx suspend/resume path.

Fixes: 76fc9452a6bf ("usb: dwc3: introduce flatten model driver of i.MX Soc")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx>
---
 drivers/usb/dwc3/dwc3-imx.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/usb/dwc3/dwc3-imx.c b/drivers/usb/dwc3/dwc3-imx.c
index 303708f7d79a..973a486b544d 100644
--- a/drivers/usb/dwc3/dwc3-imx.c
+++ b/drivers/usb/dwc3/dwc3-imx.c
@@ -288,6 +288,9 @@ static void dwc3_imx_remove(struct platform_device *pdev)
 
 static void dwc3_imx_suspend(struct dwc3_imx *dwc_imx, pm_message_t msg)
 {
+	if (dwc_imx->pm_suspended)
+		return;
+
 	if (PMSG_IS_AUTO(msg) || device_may_wakeup(dwc_imx->dev))
 		dwc3_imx_wakeup_enable(dwc_imx, msg);
 
@@ -299,6 +302,9 @@ static void dwc3_imx_resume(struct dwc3_imx *dwc_imx, pm_message_t msg)
 {
 	struct dwc3	*dwc = &dwc_imx->dwc;
 
+	if (!dwc_imx->pm_suspended)
+		return;
+
 	dwc_imx->pm_suspended = false;
 	if (!dwc_imx->wakeup_pending)
 		disable_irq_nosync(dwc_imx->irq);
-- 
2.34.1