dwc3_otg_host_init() carries the comment "should be called before Host
controller driver is started". It rewrites OCTL/OCFG, touches GUSB2PHYCFG and
re-asserts port power (OCTL.PrtPwrCtl).
dwc3_otg_irq() sets otg_restart_host ONLY when current_otg_role is already
DWC3_OTG_ROLE_HOST. The threaded handler then calls dwc3_otg_host_init()
unconditionally, so that path always ran against a live, running host -- the
exact condition the comment forbids. Re-asserting port power under a running
xHCI corrupts an in-flight command.
Observed on the RV1106 86-panel as the controller failing to answer a Stop
Endpoint command, after which xhci-hcd declares it dead and tears the bus down.
An r8152 USB NIC stalls a transfer and the controller died 8 times out of 8
between 452s and 587s. Compiling the OTG path out entirely (dr_mode=host)
survived 1810s with zero deaths, which localised it here.
On this board the event is always spurious: the dwc3 node deliberately carries
no extcon, because wiring it pins the role to peripheral on D1-modded panels,
and CONIDSTS reads 0 -- so the role cannot legitimately change while host is
current. Skip the re-init in that case and log it at debug level.
This does not remove the restart capability. dwc3_set_mode() still runs
immediately below, and if the role has genuinely changed dwc3_otg_update()
performs a proper dwc3_host_exit() before re-initialising. The only behaviour
removed is poking a running controller, which was never legitimate.
Refs flare-edge#160
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MVGTC78dgCGfRANNKjoPea
