6.6-stable review patch. If anyone has any objections, please let me know.
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From: Meng Li Meng.Li@windriver.com
commit 7838de15bb700c2898a7d741db9b1f3cbc86c136 upstream.
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.yang_2@nxp.com Cc: stable@vger.kernel.org Signed-off-by: Meng Li Meng.Li@windriver.com Acked-by: Thinh Nguyen Thinh.Nguyen@synopsys.com Link: https://lore.kernel.org/r/20240618031918.2585799-1-Meng.Li@windriver.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/dwc3/core.c | 6 ------ 1 file changed, 6 deletions(-)
--- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -2044,7 +2044,6 @@ assert_reset:
static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg) { - unsigned long flags; u32 reg;
switch (dwc->current_dr_role) { @@ -2082,9 +2081,7 @@ static int dwc3_suspend_common(struct dw 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); }
@@ -2101,7 +2098,6 @@ static int dwc3_suspend_common(struct dw
static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg) { - unsigned long flags; int ret; u32 reg;
@@ -2150,9 +2146,7 @@ static int dwc3_resume_common(struct dwc 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;