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[Medium] a failed DTR/RTS send is not retried: agreed, and stress testing confirmed it. With the change-only filter added in v9, rapidly toggling DTR/RTS filled the IP_CTRL UL ring and updates were dropped with -EAGAIN, so the modem could be left with a stale state. In v10 ->dtr_rts only records the requested state and schedules a per-port work item that sends the latest state, so a burst is coalesced into one message, and a send that fails with -EAGAIN or -ENOMEM is retried with whatever state is latest by then. The modem therefore ends up with the final state requested. [Low] sysfs unbind/rebind of mhi_wwan_dtr while an AT port is open: agreed it's a root-only corner case. Reopening the port, or changing DTR or RTS, sends the state again, so I've left it as is. pw-bot: cr