[PATCH tty-next v2] serial: asc: Conditionally use readl_relaxed (COMPILE_TEST)

[Daniel Thompson <daniel.thompson@linaro.org>]

Commit 08177ece596c ("serial: asc: Adopt readl_/writel_relaxed()) is
regressing the m68k allmodconfig build. This is due to the unconditional
use of readl_relaxed() which, although documented, does not currently
exist for m68k.

This is trivially fixable for st-asc because we can just update the
asc_in() accessor to make this conditional.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com>
Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Jiri Slaby <jslaby@suse.cz>
---

Notes:
    Will Deacon is working on a patchset to introduce readl_relaxed (and
    writel_relaxed) to all platforms. I intend to keep an eye on this
    work and will remove the conditional code in asc_in/out() when this
    is possible.
    
    Changes since v1:
    
    * Added the correct Reported-by: and removed the assertion that
      the reporter is a build bot.
    

 drivers/tty/serial/st-asc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
index a3fc167..a316584 100644
--- a/drivers/tty/serial/st-asc.c
+++ b/drivers/tty/serial/st-asc.c
@@ -151,7 +151,11 @@ static inline struct asc_port *to_asc_port(struct uart_port *port)

 static inline u32 asc_in(struct uart_port *port, u32 offset)
 {
+#ifdef readl_relaxed
 	return readl_relaxed(port->membase + offset);
+#else
+	return readl(port->membase + offset);
+#endif
 }

 static inline void asc_out(struct uart_port *port, u32 offset, u32 value)
--
1.9.3