[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <CAKzKK0rezBC_9zwzkmeejGXtO3W+fTDOKsS26CsvhW+WwKRySA@mail.gmail.com>
Date: Wed, 28 May 2025 18:07:10 +0800
From: Kuen-Han Tsai <khtsai@...gle.com>
To: "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>
Cc: Thinh Nguyen <Thinh.Nguyen@...opsys.com>,
"linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"stable@...r.kernel.org" <stable@...r.kernel.org>
Subject: Re: [PATCH v4] usb: dwc3: Abort suspend on soft disconnect failure
On Wed, May 28, 2025 at 4:23 PM gregkh@...uxfoundation.org
<gregkh@...uxfoundation.org> wrote:
>
> On Wed, May 28, 2025 at 03:35:15PM +0800, Kuen-Han Tsai wrote:
> > On Sat, Apr 19, 2025 at 9:24 AM Thinh Nguyen <Thinh.Nguyen@...opsys.com> wrote:
> > >
> > > On Wed, Apr 16, 2025, Kuen-Han Tsai wrote:
> > > > When dwc3_gadget_soft_disconnect() fails, dwc3_suspend_common() keeps
> > > > going with the suspend, resulting in a period where the power domain is
> > > > off, but the gadget driver remains connected. Within this time frame,
> > > > invoking vbus_event_work() will cause an error as it attempts to access
> > > > DWC3 registers for endpoint disabling after the power domain has been
> > > > completely shut down.
> > > >
> > > > Abort the suspend sequence when dwc3_gadget_suspend() cannot halt the
> > > > controller and proceeds with a soft connect.
> > > >
> > > > Fixes: 9f8a67b65a49 ("usb: dwc3: gadget: fix gadget suspend/resume")
> > > > CC: stable@...r.kernel.org
> > > > Signed-off-by: Kuen-Han Tsai <khtsai@...gle.com>
> > > > ---
> > > >
> > > > Kernel panic - not syncing: Asynchronous SError Interrupt
> > > > Workqueue: events vbus_event_work
> > > > Call trace:
> > > > dump_backtrace+0xf4/0x118
> > > > show_stack+0x18/0x24
> > > > dump_stack_lvl+0x60/0x7c
> > > > dump_stack+0x18/0x3c
> > > > panic+0x16c/0x390
> > > > nmi_panic+0xa4/0xa8
> > > > arm64_serror_panic+0x6c/0x94
> > > > do_serror+0xc4/0xd0
> > > > el1h_64_error_handler+0x34/0x48
> > > > el1h_64_error+0x68/0x6c
> > > > readl+0x4c/0x8c
> > > > __dwc3_gadget_ep_disable+0x48/0x230
> > > > dwc3_gadget_ep_disable+0x50/0xc0
> > > > usb_ep_disable+0x44/0xe4
> > > > ffs_func_eps_disable+0x64/0xc8
> > > > ffs_func_set_alt+0x74/0x368
> > > > ffs_func_disable+0x18/0x28
> > > > composite_disconnect+0x90/0xec
> > > > configfs_composite_disconnect+0x64/0x88
> > > > usb_gadget_disconnect_locked+0xc0/0x168
> > > > vbus_event_work+0x3c/0x58
> > > > process_one_work+0x1e4/0x43c
> > > > worker_thread+0x25c/0x430
> > > > kthread+0x104/0x1d4
> > > > ret_from_fork+0x10/0x20
> > > >
> > > > ---
> > > > Changelog:
> > > >
> > > > v4:
> > > > - correct the mistake where semicolon was forgotten
> > > > - return -EAGAIN upon dwc3_gadget_suspend() failure
> > > >
> > > > v3:
> > > > - change the Fixes tag
> > > >
> > > > v2:
> > > > - move declarations in separate lines
> > > > - add the Fixes tag
> > > >
> > > > ---
> > > > drivers/usb/dwc3/core.c | 9 +++++++--
> > > > drivers/usb/dwc3/gadget.c | 22 +++++++++-------------
> > > > 2 files changed, 16 insertions(+), 15 deletions(-)
> > > >
> > > > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > > > index 66a08b527165..f36bc933c55b 100644
> > > > --- a/drivers/usb/dwc3/core.c
> > > > +++ b/drivers/usb/dwc3/core.c
> > > > @@ -2388,6 +2388,7 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
> > > > {
> > > > u32 reg;
> > > > int i;
> > > > + int ret;
> > > >
> > > > if (!pm_runtime_suspended(dwc->dev) && !PMSG_IS_AUTO(msg)) {
> > > > dwc->susphy_state = (dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0)) &
> > > > @@ -2406,7 +2407,9 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
> > > > case DWC3_GCTL_PRTCAP_DEVICE:
> > > > if (pm_runtime_suspended(dwc->dev))
> > > > break;
> > > > - dwc3_gadget_suspend(dwc);
> > > > + ret = dwc3_gadget_suspend(dwc);
> > > > + if (ret)
> > > > + return ret;
> > > > synchronize_irq(dwc->irq_gadget);
> > > > dwc3_core_exit(dwc);
> > > > break;
> > > > @@ -2441,7 +2444,9 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
> > > > break;
> > > >
> > > > if (dwc->current_otg_role == DWC3_OTG_ROLE_DEVICE) {
> > > > - dwc3_gadget_suspend(dwc);
> > > > + ret = dwc3_gadget_suspend(dwc);
> > > > + if (ret)
> > > > + return ret;
> > > > synchronize_irq(dwc->irq_gadget);
> > > > }
> > > >
> > > > diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> > > > index 89a4dc8ebf94..630fd5f0ce97 100644
> > > > --- a/drivers/usb/dwc3/gadget.c
> > > > +++ b/drivers/usb/dwc3/gadget.c
> > > > @@ -4776,26 +4776,22 @@ int dwc3_gadget_suspend(struct dwc3 *dwc)
> > > > int ret;
> > > >
> > > > ret = dwc3_gadget_soft_disconnect(dwc);
> > > > - if (ret)
> > > > - goto err;
> > > > -
> > > > - spin_lock_irqsave(&dwc->lock, flags);
> > > > - if (dwc->gadget_driver)
> > > > - dwc3_disconnect_gadget(dwc);
> > > > - spin_unlock_irqrestore(&dwc->lock, flags);
> > > > -
> > > > - return 0;
> > > > -
> > > > -err:
> > > > /*
> > > > * Attempt to reset the controller's state. Likely no
> > > > * communication can be established until the host
> > > > * performs a port reset.
> > > > */
> > > > - if (dwc->softconnect)
> > > > + if (ret && dwc->softconnect) {
> > > > dwc3_gadget_soft_connect(dwc);
> > > > + return -EAGAIN;
> > >
> > > This may make sense to have -EAGAIN for runtime suspend. I supposed this
> > > should be fine for system suspend since it doesn't do anything special
> > > for this error code.
> > >
> > > When you tested runtime suspend, did you observe that the device
> > > successfully going into suspend on retry?
> > >
> > > In any case, I think this should be good. Thanks for the fix:
> > >
> > > Acked-by: Thinh Nguyen <Thinh.Nguyen@...opsys.com>
> > >
> > > Thanks,
> > > Thinh
> >
> > Hi Greg,
> >
> > It looks like this patch hasn't been cherry-picked into the usb-next
> > branch yet. Am I missing something?
>
> It's somehow not in my queue anymore, sorry. Can you please resend it
> and I'll pick it up after -rc1 is out.
>
> thanks,
>
> greg k-h
Hi Greg,
Sent out the v5 patch, which includes Thinh Nguyen's Acked-by tag. Thanks!
https://lore.kernel.org/linux-usb/20250528100315.2162699-1-khtsai@google.com/T/#u
Regards,
Kuen-Han
Powered by blists - more mailing lists