Hi Sebastian, >>> UART devices is expected to be enumerated by SerDev subsystem. >>> >>> During ACPI scan, serial devices behind SPI, I2C or UART buses are not >>> enumerated, allowing them to be enumerated by their respective parents. >>> >>> Rename *spi_i2c_slave* to *serial_bus_slave* as this will be used for serial >>> devices on serial buses (SPI, I2C or UART). >>> >>> On Macs an empty ResourceTemplate is returned for uart slaves. >>> Instead the device properties "baud", "parity", "dataBits", "stopBits" are >>> provided. Add a check for "baud" in acpi_is_serial_bus_slave(). >>> >>> Signed-off-by: Frédéric Danis <frederic.danis.oss@xxxxxxxxx> >> >> So just to reiterate what I just mentioned in a comment to one of Hans's >> hci_bcm patches: >> >> This one would silently break PM for such devices on any system which >> does not have serdev enabled (as the corresponding platform devices >> would no longer be registered). And with serdev enabled, hciattach >> (btattach) would start failing as the tty device would no longer be >> registered (but I assume everyone is aware of that, and fine with it, by >> now). >> >> Perhaps the hci_bcm driver should start depending on >> SERIAL_DEV_CTRL_TTYPORT when ACPI is enabled? > > ACPI and DT both need SERIAL_DEV_CTRL_TTYPORT to work properly, > since SERIAL_DEV_CTRL_TTYPORT is the only controller implemented > for serdev. If any other controller is implemented that one could > also be used. > > I wonder if we should just hide SERIAL_DEV_CTRL_TTYPORT and enable > it together with SERDEV. I suspect that we won't see any other > controller (it would be a UART device, that is not registered as > tty device) in the next few years and the extra option seems to > confuse people. I wonder if we should just default SERIAL_DEV_CTRL_TTYPORT=y when DT or ACPI is enabled. Then no driver would have to select or depend on it. Regards Marcel -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
