[PATCH v4 1/2] powerpc/legacy_serial: Handle SERIAL_8250_FSL=n build failures

[Uwe Kleine-König]

With SERIAL_8250=y and SERIAL_8250_FSL_CONSOLE=n the both
IS_ENABLED(CONFIG_SERIAL_8250) and IS_REACHABLE(CONFIG_SERIAL_8250)
evaluate to true and so fsl8250_handle_irq() is used. However this
function is only available if CONFIG_SERIAL_8250_CONSOLE=y (and thus
SERIAL_8250_FSL=y).

To prepare SERIAL_8250_FSL becoming tristate and being enabled in more
cases, check for IS_REACHABLE(CONFIG_SERIAL_8250_FSL) before making use
of fsl8250_handle_irq(). This check is correct with and without the
change to make SERIAL_8250_FSL modular.

Reported-by: Randy Dunlap <rdun...@infradead.org>
Fixes: 66eff0ef528b ("powerpc/legacy_serial: Warn about 8250 devices operated 
without active FSL workarounds")
Signed-off-by: Uwe Kleine-König <u.kleine-koe...@pengutronix.de>
---
 arch/powerpc/kernel/legacy_serial.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/legacy_serial.c 
b/arch/powerpc/kernel/legacy_serial.c
index fdbd85aafeb1..6ee65741dbd5 100644
--- a/arch/powerpc/kernel/legacy_serial.c
+++ b/arch/powerpc/kernel/legacy_serial.c
@@ -510,7 +510,7 @@ static void __init fixup_port_irq(int index,
 
        if (IS_ENABLED(CONFIG_SERIAL_8250) &&
            of_device_is_compatible(np, "fsl,ns16550")) {
-               if (IS_REACHABLE(CONFIG_SERIAL_8250)) {
+               if (IS_REACHABLE(CONFIG_SERIAL_8250_FSL)) {
                        port->handle_irq = fsl8250_handle_irq;
                        port->has_sysrq = 
IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
                } else {
-- 
2.39.2