diff options
| author | Meng Li <Meng.Li@windriver.com> | 2024-06-18 06:19:18 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-06-20 20:36:45 +0300 |
| commit | 7838de15bb700c2898a7d741db9b1f3cbc86c136 (patch) | |
| tree | 62e3cb0300853569f1d4e484a76602e9971e78ca /drivers/usb/dwc3/core.c | |
| parent | c68942624e254a4e8a65afcd3c17ed95acda5489 (diff) | |
| download | linux-7838de15bb700c2898a7d741db9b1f3cbc86c136.tar.xz | |
usb: dwc3: core: remove lock of otg mode during gadget suspend/resume to avoid deadlock
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>
Diffstat (limited to 'drivers/usb/dwc3/core.c')
| -rw-r--r-- | drivers/usb/dwc3/core.c | 6 |
1 files changed, 0 insertions, 6 deletions
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 7ee61a89520b..9d47c3aa5777 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -2250,7 +2250,6 @@ assert_reset: static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg) { - unsigned long flags; u32 reg; int i; @@ -2293,9 +2292,7 @@ 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); } @@ -2312,7 +2309,6 @@ 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; int i; @@ -2366,9 +2362,7 @@ 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; |