The SMSC FDC37M817 Super I/O chip has a configuration feature that lets it support special UART divisor values of 32770 and 32769 for bit rates of 230400 and 460800 bits per second respectively. Our 8250 driver core provides support for these special divisors via the UPF_MAGIC_MULTIPLIER flag, and YAMON firmware unconditionally configures the Super I/O chip with these divisors enabled as well, so all we need to do in platform setup for these bit rates to work is to set the flag. Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxxxxx> --- arch/mips/mti-malta/malta-platform.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) linux-mips-malta-smsc-uart-magic-multiplier.diff Index: linux-malta-cbus-uart/arch/mips/mti-malta/malta-platform.c =================================================================== --- linux-malta-cbus-uart.orig/arch/mips/mti-malta/malta-platform.c +++ linux-malta-cbus-uart/arch/mips/mti-malta/malta-platform.c @@ -33,7 +33,8 @@ .irq = int, \ .uartclk = 1843200, \ .iotype = UPIO_PORT, \ - .flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST, \ + .flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | \ + UPF_MAGIC_MULTIPLIER, \ .regshift = 0, \ }
