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@vger.kernel.org Signed-off-by: Kuen-Han Tsai khtsai@google.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; + }
- 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) -- 2.49.0.604.gff1f9ca942-goog