On Thu, Mar 20, 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.
>
> CC: stable@xxxxxxxxxxxxxxx
Please add Fixes tag.
> Signed-off-by: Kuen-Han Tsai <khtsai@xxxxxxxxxx>
> ---
>
> 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
>
> ---
> drivers/usb/dwc3/core.c | 10 +++++++---
> drivers/usb/dwc3/gadget.c | 22 +++++++++-------------
> 2 files changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 66a08b527165..d64d17677bdb 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -2387,7 +2387,7 @@ static int dwc3_core_init_for_resume(struct dwc3 *dwc)
> static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
> {
> u32 reg;
> - int i;
> + int i, ret;
Minor nit: Can we keep declarations in separate lines.
>
> if (!pm_runtime_suspended(dwc->dev) && !PMSG_IS_AUTO(msg)) {
> dwc->susphy_state = (dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0)) &
> @@ -2406,7 +2406,9 @@ 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 +2443,9 @@ 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..316c1589618e 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 ret;
> + }
>
> - return ret;
> + spin_lock_irqsave(&dwc->lock, flags);
> + if (dwc->gadget_driver)
> + dwc3_disconnect_gadget(dwc);
> + spin_unlock_irqrestore(&dwc->lock, flags);
> +
> + return 0;
> }
>
> int dwc3_gadget_resume(struct dwc3 *dwc)
> --
> 2.49.0.395.g12beb8f557-goog
>
The rest looks good.
Thanks,
Thinh
