arm: mvebu: fix coherency_late_init() for multiplatform

As noticed by Arnaud Patard (Rtp) <arnaud.patard@rtp-net.org>, commit
865e0527d2d7 ('arm: mvebu: avoid hardcoded virtual address in
coherency code') added a postcore_initcall() to register the bus
notifier that the mvebu code needs to apply correct DMA operations on
its platform devices breaks the multiplatform boot on other platforms,
because the bus notifier registration is unconditional.

This commit fixes that by registering the bus notifier only if we have
the mvebu coherency unit described in the Device Tree. The conditional
used is exactly the same in which the bus_register_notifier() call was
originally enclosed before 865e0527d2d7 ('arm: mvebu: avoid hardcoded
virtual address in coherency code').

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reported-by: Arnaud Patard (Rtp) <arnaud.patard@rtp-net.org>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-mvebu/coherency.c
index 32fcf69f42021515f8a6ea4019bd003fd00012e9..be117591f7f256ca04c47c40d7fabd38aa081161 100644 (file)
--- a/arch/arm/mach-mvebu/coherency.c
+++ b/arch/arm/mach-mvebu/coherency.c
@@ -147,8 +147,9 @@ int __init coherency_init(void)
 
 static int __init coherency_late_init(void)
 {
-       bus_register_notifier(&platform_bus_type,
-                             &mvebu_hwcc_platform_nb);
+       if (of_find_matching_node(NULL, of_coherency_table))
+               bus_register_notifier(&platform_bus_type,
+                                     &mvebu_hwcc_platform_nb);
        return 0;
 }