The linux/mtd/map.h header file is included by a couple of
platform specific files that are built even when CONFIG_MTD
is disabled, and we always get

 warning "No CONFIG_MTD_MAP_BANK_WIDTH_xx selected. No NOR chip support can work"

in that case. This adds an #ifdef around the pointless warning,
as everything is really fine when we don't build the drivers
anyway.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---

quoted

I'm actually still getting the warnings for any file that includes <linux/mtd/map.h>
while CONFIG_MTD is disabled. I have a fix now that I'm testing overnight
and plan to post tomorrow, then we can decide whether it should be part of
the same patch, or we should have two separate patches.

The patch fixes the remaining warnings I see on ARM randconfigs in this file,
and I think it makes sense to keep it as a separate patch, as these are really
distinct problems even thought the symptom is the same.

Please apply both.

diff --git a/include/linux/mtd/map.h b/include/linux/mtd/map.h
index 366cf77953b5..58f3ba709ade 100644
--- a/include/linux/mtd/map.h
+++ b/include/linux/mtd/map.h

@@ -142,7 +142,9 @@
 #endif
 
 #ifndef map_bankwidth
+#ifdef CONFIG_MTD
 #warning "No CONFIG_MTD_MAP_BANK_WIDTH_xx selected. No NOR chip support can work"
+#endif
 static inline int map_bankwidth(void *map)
 {
 	BUG();