Add configurable device vendor ID (libcec_configuration.iDeviceVendorId)#714
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Add configurable device vendor ID (libcec_configuration.iDeviceVendorId)#714Andy1210 wants to merge 1 commit into
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libCEC hardcodes CEC_VENDOR_PULSE_EIGHT as the identity of the devices it handles: the Linux adapter registers it via CEC_ADAP_S_LOG_ADDRS (the kernel then broadcasts it in <Device Vendor ID> at every logical address claim) and devices marked as handled by libCEC answer <Give Device Vendor ID> with it until a vendor-specific handler replaces the default. Some TVs key protocol features on that identity. LG SIMPLINK is the reproducible case: the TV only forwards remote keys to devices whose vendor ID reads LG (0x00e091), queries the vendor ~200 ms after a new device appears — before the LG (SL) handler is installed — and caches the first answer per logical address, so libCEC's built-in LG masquerade loses that race and the device never receives remote keys. Add an iDeviceVendorId field to libcec_configuration (default CEC_VENDOR_UNKNOWN = keep today's behavior) so the application can present a consistent vendor identity from the very first bus transaction, plus a --vendor-id option in cec-client to set it. Validated on a Raspberry Pi 5 (vc4_hdmi, kernel CEC API, kernel 6.18) against an LG TV where the race reproduces deterministically: with --vendor-id e091 the TV completes the SIMPLINK handshake and forwards remote keys; without it the TV probes the device forever and forwards nothing. Default behavior is unchanged.
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libCEC hardcodes
CEC_VENDOR_PULSE_EIGHTas the identity of the devices it handles — the Linux adapter registers it viaCEC_ADAP_S_LOG_ADDRS(the kernel then broadcasts<Device Vendor ID>with it at every logical-address claim), and devices handled by libCEC answer<Give Device Vendor ID>with it until a vendor-specific handler replaces the default.Some TVs key protocol features on that identity. The reproducible case is LG SIMPLINK: the TV only forwards remote keys to devices whose vendor ID reads LG (
0x00e091), queries the vendor ~200 ms after a device appears — before the SL handler is installed — and caches the first answer per logical address, so the built-in LG masquerade loses the race and the device never receives remote keys.This adds
iDeviceVendorIdtolibcec_configuration(defaultCEC_VENDOR_UNKNOWN= current behavior) so an application can present a consistent vendor identity from the first bus transaction, plus a--vendor-idoption in cec-client.Changes
libcec_configuration.iDeviceVendorId(new field, defaultCEC_VENDOR_UNKNOWN), copied inCCECClient::Get/SetConfiguration.CEC_ADAP_S_LOG_ADDRSinOpen()andSetLogicalAddresses()) announces the configured vendor when set, otherwiseCEC_VENDOR_PULSE_EIGHTas before.CCECBusDevice::SetDeviceStatus(CEC_DEVICE_STATUS_HANDLED_BY_LIBCEC)uses the configured vendor for own devices, so<Give Device Vendor ID>replies match from the first transaction.cec-client --vendor-id <hex>to set it from the CLI.Validation
Tested on a Raspberry Pi 5 (vc4_hdmi, kernel CEC API, kernel 6.18) against an LG TV where the race reproduces deterministically: with
--vendor-id e091the TV completes the SIMPLINK handshake and forwards remote keys; without it it probes forever and forwards nothing. Default behavior is unchanged wheniDeviceVendorIdis left atCEC_VENDOR_UNKNOWN.