When config CONFIG_USB_DWC3_DUAL_ROLE is selected, and trigger system
to enter suspend status with below command:
echo mem > /sys/power/state
There will be a deadlock issue occurring. Detailed invoking path as
below:
dwc3_suspend_common()
spin_lock_irqsave(&dwc->lock, flags); <-- 1st
dwc3_gadget_suspend(dwc);
dwc3_gadget_soft_disconnect(dwc);
spin_lock_irqsave(&dwc->lock, flags); <-- 2nd
This issue is exposed by commit c7ebd8149ee5 ("usb: dwc3: gadget: Fix
NULL pointer dereference in dwc3_gadget_suspend") that removes the code
of checking whether dwc->gadget_driver is NULL or not. It causes the
following code is executed and deadlock occurs when trying to get the
spinlock. In fact, the root cause is the commit 5265397f9442("usb: dwc3:
Remove DWC3 locking during gadget suspend/resume") that forgot to remove
the lock of otg mode. So, remove the redundant lock of otg mode during
gadget suspend/resume.
Fixes: 5265397f9442 ("usb: dwc3: Remove DWC3 locking during gadget
suspend/resume")
Cc: Xu Yang <xu.yan...@nxp.com>
Cc: sta...@vger.kernel.org
Signed-off-by: Meng Li <meng...@windriver.com>
---
drivers/usb/dwc3/core.c | 6 ------
1 file changed, 6 deletions(-)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index a8fb10cc65bc..9bb4ab409bbb 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -2112,7 +2112,6 @@ static int dwc3_core_init_for_resume(struct dwc3 *dwc)
static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
{
- unsigned long flags;
u32 reg;
switch (dwc->current_dr_role) {
@@ -2150,9 +2149,7 @@ static int dwc3_suspend_common(struct dwc3 *dwc,
pm_message_t msg)
break;
if (dwc->current_otg_role == DWC3_OTG_ROLE_DEVICE) {
- spin_lock_irqsave(&dwc->lock, flags);
dwc3_gadget_suspend(dwc);
- spin_unlock_irqrestore(&dwc->lock, flags);
synchronize_irq(dwc->irq_gadget);
}
@@ -2169,7 +2166,6 @@ static int dwc3_suspend_common(struct dwc3 *dwc,
pm_message_t msg)
static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
{
- unsigned long flags;
int ret;
u32 reg;
@@ -2227,9 +2223,7 @@ static int dwc3_resume_common(struct dwc3 *dwc,
pm_message_t msg)
if (dwc->current_otg_role == DWC3_OTG_ROLE_HOST) {
dwc3_otg_host_init(dwc);
} else if (dwc->current_otg_role == DWC3_OTG_ROLE_DEVICE) {
- spin_lock_irqsave(&dwc->lock, flags);
dwc3_gadget_resume(dwc);
- spin_unlock_irqrestore(&dwc->lock, flags);
}
break;
--
2.34.1
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