GMSL1 devices automatically become I2C master or slave devices. The usual concern is what the slave timeout is, but there is a master timeout as well and they interact.
Many Maxim GMSL1 SerDes parts support I2C for both ends of the control channel (I2C-I2C). This channel is used to program the parts and address parts connected to one side of a SerDes system form a microcontroller at the other side. All parts automatically become a slave or master (on an I2C transaction basis) determined from the protocol.
At the device on the microcontroller side, commands can lost by causes such as a temporarily noisy or disconnected GMSL1 link. In this case, it is important that the GMSL1 part timeout so that it can receive future I2C commands. There is a programmable I2C slave timeout in all I2C-I2C parts, which should be set greater than the expected response delay (the default value works in most cases.
At the device on the opposite side of the GMSL1 link from the microcontroller, there is much less concern with lost commands because there is only a short pcb trace connecting the SerDes to the part being addressed. However, in order to make sure that the part can never be permanently in an unknown state, Maxim added a 512us master timeout to all parts. This is normally not triggered.
In the case where a device on the opposite side of the GMSL1 link from the microcontroller has a long reponse time, the default setup, where the slave timeout is longer than the master timeout can cause a problem (see I2C specifications for protocol details). In this case, the slave timeout at the microcontroller side should be set less than the master timeout for correct operation.