git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From 7838de15bb700c2898a7d741db9b1f3cbc86c136 Mon Sep 17 00:00:00 2001
   2 From: Meng Li <Meng.Li@windriver.com>
   3 Date: Tue, 18 Jun 2024 11:19:18 +0800
   4 Subject: usb: dwc3: core: remove lock of otg mode during gadget suspend/resume to avoid deadlock
   5
   6 From: Meng Li <Meng.Li@windriver.com>
   7
   8 commit 7838de15bb700c2898a7d741db9b1f3cbc86c136 upstream.
   9
  10 When config CONFIG_USB_DWC3_DUAL_ROLE is selected, and trigger system
  11 to enter suspend status with below command:
  12 echo mem > /sys/power/state
  13 There will be a deadlock issue occurring. Detailed invoking path as
  14 below:
  15 dwc3_suspend_common()
  16     spin_lock_irqsave(&dwc->lock, flags);              <-- 1st
  17     dwc3_gadget_suspend(dwc);
  18         dwc3_gadget_soft_disconnect(dwc);
  19             spin_lock_irqsave(&dwc->lock, flags);      <-- 2nd
  20 This issue is exposed by commit c7ebd8149ee5 ("usb: dwc3: gadget: Fix
  21 NULL pointer dereference in dwc3_gadget_suspend") that removes the code
  22 of checking whether dwc->gadget_driver is NULL or not. It causes the
  23 following code is executed and deadlock occurs when trying to get the
  24 spinlock. In fact, the root cause is the commit 5265397f9442("usb: dwc3:
  25 Remove DWC3 locking during gadget suspend/resume") that forgot to remove
  26 the lock of otg mode. So, remove the redundant lock of otg mode during
  27 gadget suspend/resume.
  28
  29 Fixes: 5265397f9442 ("usb: dwc3: Remove DWC3 locking during gadget suspend/resume")
  30 Cc: Xu Yang <xu.yang_2@nxp.com>
  31 Cc: stable@vger.kernel.org
  32 Signed-off-by: Meng Li <Meng.Li@windriver.com>
  33 Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
  34 Link: https://lore.kernel.org/r/20240618031918.2585799-1-Meng.Li@windriver.com
  35 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  36 ---
  37  drivers/usb/dwc3/core.c |    6 ------
  38  1 file changed, 6 deletions(-)
  39
  40 --- a/drivers/usb/dwc3/core.c
  41 +++ b/drivers/usb/dwc3/core.c
  42 @@ -2084,7 +2084,6 @@ assert_reset:
  43
  44  static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
  45  {
  46 -       unsigned long   flags;
  47         u32 reg;
  48
  49         switch (dwc->current_dr_role) {
  50 @@ -2122,9 +2121,7 @@ static int dwc3_suspend_common(struct dw
  51                         break;
  52
  53                 if (dwc->current_otg_role == DWC3_OTG_ROLE_DEVICE) {
  54 -                       spin_lock_irqsave(&dwc->lock, flags);
  55                         dwc3_gadget_suspend(dwc);
  56 -                       spin_unlock_irqrestore(&dwc->lock, flags);
  57                         synchronize_irq(dwc->irq_gadget);
  58                 }
  59
  60 @@ -2141,7 +2138,6 @@ static int dwc3_suspend_common(struct dw
  61
  62  static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
  63  {
  64 -       unsigned long   flags;
  65         int             ret;
  66         u32             reg;
  67
  68 @@ -2190,9 +2186,7 @@ static int dwc3_resume_common(struct dwc
  69                 if (dwc->current_otg_role == DWC3_OTG_ROLE_HOST) {
  70                         dwc3_otg_host_init(dwc);
  71                 } else if (dwc->current_otg_role == DWC3_OTG_ROLE_DEVICE) {
  72 -                       spin_lock_irqsave(&dwc->lock, flags);
  73                         dwc3_gadget_resume(dwc);
  74 -                       spin_unlock_irqrestore(&dwc->lock, flags);
  75                 }
  76
  77                 break;