On 11/21/2018 02:17 PM, Andy Shevchenko wrote: > On Wed, Nov 21, 2018 at 12:51:28PM -0500, Prarit Bhargava wrote: >> On 11/21/2018 08:43 AM, Andy Shevchenko wrote: >>> Since SPCR 1.04 [1] the baud rate of 0 means a preconfigured state of UART. >>> Assume firmware or bootloader configures console correctly. >>> >>> [1]: https://docs.microsoft.com/en-us/windows-hardware/drivers/serports/serial-port-console-redirection-table > >>> + if (!baud_rate) { >>> snprintf(opts, sizeof(opts), "%s,%s,0x%llx", uart, iotype, >>> table->serial_port.address); >>> } else { > >> OOC what happens if you pass in opts="uart,io,0x3f8,0" to setup_earlycon() and >> add_preferred_console() ? > > Nothing critical for 8250, though > a) we have a plenty of UART drivers and I don't check them; > b) the code above (avoidance of 0 to be baud rate parameter) is already in > upstream by some reason (see a) as well). > > So, I wouldn't touch that logic. > Agreed. I was thinking that if ",0" was accepted in that code it would lead towards a further cleanup. Reviewed-by: Prarit Bhargava <prarit@xxxxxxxxxx> P.
