viacuda: fix livelock caused by autopoll clobbering in-progress transactions#168
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dingusdev merged 1 commit intodingusdev:masterfrom Feb 21, 2026
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autopoll_handler()is called on every SDL event loop iteration. When a poll returned data while a Cuda transaction was already in progress (old_tip=0ortreq=0), the handler would log a warning but proceed anyway — overwritingout_buf, asserting TREQ, and scheduling a new SR interrupt. This prevented the guest from ever completing the previous transaction, causing a livelock where the emulated Mac appeared frozen (cursor still moves since mouse events are handled separately).The same issue affected one-second time packets sent during the
one_sec_modepath.Additionally,
AdbDevice::poll()callsget_register_0()which destructively consumes keyboard events and mouse deltas. Even if we had returned after the warning, the ADB data would already be lost.Fix by moving the busy check before the
poll()call so that when a transaction is in progress, the handler returns immediately without polling ADB devices. Events remain queued in ADB device buffers and are picked up on the next cycle when the bus is idle.