> -----Original Message-----
> From: Bruce Ashfield <bruce.ashfi...@gmail.com>
> Sent: Tuesday, June 18, 2024 9:21 PM
> To: Li, Meng <meng...@windriver.com>
> Cc: linux-yocto@lists.yoctoproject.org
> Subject: Re: [linux-yocto] [v2 PATCH] usb: dwc3: core: remove lock of otg
> mode during gadget suspend/resume to avoid deadlock
>
> CAUTION: This email comes from a non Wind River email account!
> Do not click links or open attachments unless you recognize the sender and
> know the content is safe.
>
> On Tue, Jun 18, 2024 at 8:35 AM Li, Meng <meng...@windriver.com> wrote:
> >
> >
> >
> > > -----Original Message-----
> > > From: linux-yocto@lists.yoctoproject.org
> > > <linux-yocto@lists.yoctoproject.org>
> > > On Behalf Of Bruce Ashfield
> > > Sent: Tuesday, June 18, 2024 8:29 PM
> > > To: Li, Meng <meng...@windriver.com>
> > > Cc: linux-yocto@lists.yoctoproject.org
> > > Subject: Re: [linux-yocto] [v2 PATCH] usb: dwc3: core: remove lock
> > > of otg mode during gadget suspend/resume to avoid deadlock
> > >
> > > CAUTION: This email comes from a non Wind River email account!
> > > Do not click links or open attachments unless you recognize the
> > > sender and know the content is safe.
> > >
> > > On Tue, Jun 18, 2024 at 12:02 AM Meng Li <meng...@windriver.com>
> wrote:
> > > >
> > > > 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.
> > > >
> > >
> > > I'll apply this to v6.6/standard/base and linux-yocto-dev
> > > v6.10/standard/base.
> > >
> >
> > This patch works fine for v6.6/standard/base.
> > About the v6.10/standard/base branch, there is code context conflict.
>
> I assume that the maintainers patch or other changes are protecting
> 6.10 from the issue ?
>
Yes!
I think my v2 patch for mainline will be merged into one of v6.10-rc, and then
this issue will be fixed in v6.10.
Thanks,
LImeng
> >
> > > Correct me if I'm wrong and you'd still prefer it on the BSP branches.
> > >
> >
> > Yes! I would like to it on BSP branches, too.
>
> This is now merged. Whenever something goes to standard/base, it will
> always be on all BSPs as well since my scripts merge from the core branches to
> all BSP leaf branches on every change.
>
> Bruce
>
> >
> > Thanks,
> > Limeng
> >
> > > Bruce
> > >
> > > > 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
> > > >
> > >
> > >
> > > --
> > > - Thou shalt not follow the NULL pointer, for chaos and madness
> > > await thee at its end
> > > - "Use the force Harry" - Gandalf, Star Trek II
>
>
>
> --
> - Thou shalt not follow the NULL pointer, for chaos and madness await thee at
> its end
> - "Use the force Harry" - Gandalf, Star Trek II
-=-=-=-=-=-=-=-=-=-=-=-
Links: You receive all messages sent to this group.
View/Reply Online (#14067):
https://lists.yoctoproject.org/g/linux-yocto/message/14067
Mute This Topic: https://lists.yoctoproject.org/mt/106735260/21656
Group Owner: linux-yocto+ow...@lists.yoctoproject.org
Unsubscribe: https://lists.yoctoproject.org/g/linux-yocto/unsub
[arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
