Hello, this is the fourth iteration of trying to make the FSL workaround code active even without 8250 console support. The first patch is a fix for commit 66eff0ef528b (powerpc/legacy_serial: Warn about 8250 devices operated without active FSL workarounds) that currently is in tty-next. This patch originates from my v3 that was only partially applied. (That is a lame excuse though. While the applying the full series would not have shown this problem, bisection would still have a problem.) The second patch makes SERIAL_8250_FSL tristate and thus allows this to be enabled also with SERIAL_8250=m. This is also the relevant change since v3, where 8250_fsl.o was linked into 8250-base.ko. This series is build tested on amd64 and powerpc with all 27 possible configurations for SERIAL_8250={y,m,n} SERIAL_8250_FSL={y,m,n} SERIAL_OF_PLATFORM={y,m,n} using: choices=(y m n) for i in $(seq 0 26); do perl -p -e "s/SERIAL_8250=y/SERIAL_8250=${choices[$(((i / 9) % 3))]}/; s/SERIAL_8250_FSL=y/SERIAL_8250_FSL=${choices[$(((i / 3) % 3))]}/; s/SERIAL_OF_PLATFORM=y/SERIAL_OF_PLATFORM=${choices[$((i % 3))]}/;" .config-pre > .config && make -j 12 || break; done with .config-pre having COMPILE_TEST=y so this time there shouldn't be a build regression. (Not all 27 variants are possible, so some valid configurations are tested twice or more, but that's still good enough.) The patches have no strong dependency on each other, so they could go in via different trees. But given that 66eff0ef528b is in tty-next, taking both via tty sounds most sensible. Best regards Uwe Uwe Kleine-König (2): powerpc/legacy_serial: Handle SERIAL_8250_FSL=n build failures serial: 8250: Apply FSL workarounds also without SERIAL_8250_CONSOLE arch/powerpc/kernel/legacy_serial.c | 2 +- drivers/tty/serial/8250/8250_fsl.c | 3 +++ drivers/tty/serial/8250/8250_of.c | 2 +- drivers/tty/serial/8250/Kconfig | 6 +++--- 4 files changed, 8 insertions(+), 5 deletions(-) base-commit: 66eff0ef528b6d6e9a45b68f6cd969dcbe7b800a -- 2.39.2