[PATCH 4.0 087/105] bus: mvebu-mbus: do not set WIN_CTRL_SYNCBARRIER on non io-coherent platforms.

[Greg Kroah-Hartman]

4.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Nicolas Schichan <nschichan@xxxxxxxxxx>

commit 8c9e06e64768665503e778088a39ecff3a6f2e0c upstream.

Commit a0b5cd4ac2d6 ("bus: mvebu-mbus: use automatic I/O
synchronization barriers") enabled the usage of automatic I/O
synchronization barriers by enabling bit WIN_CTRL_SYNCBARRIER in the
control registers of MBus windows, but on non io-coherent platforms
(orion5x, kirkwood and dove) the WIN_CTRL_SYNCBARRIER bit in
the window control register is either reserved (all windows except 6
and 7) or enables read-only protection (windows 6 and 7).

Signed-off-by: Nicolas Schichan <nschichan@xxxxxxxxxx>
Reviewed-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
Fixes: a0b5cd4ac2d6 ("bus: mvebu-mbus: use automatic I/O synchronization barriers")
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/bus/mvebu-mbus.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/bus/mvebu-mbus.c
+++ b/drivers/bus/mvebu-mbus.c
@@ -70,6 +70,7 @@
  */
 #define WIN_CTRL_OFF		0x0000
 #define   WIN_CTRL_ENABLE       BIT(0)
+/* Only on HW I/O coherency capable platforms */
 #define   WIN_CTRL_SYNCBARRIER  BIT(1)
 #define   WIN_CTRL_TGT_MASK     0xf0
 #define   WIN_CTRL_TGT_SHIFT    4
@@ -323,8 +324,9 @@ static int mvebu_mbus_setup_window(struc
 	ctrl = ((size - 1) & WIN_CTRL_SIZE_MASK) |
 		(attr << WIN_CTRL_ATTR_SHIFT)    |
 		(target << WIN_CTRL_TGT_SHIFT)   |
-		WIN_CTRL_SYNCBARRIER             |
 		WIN_CTRL_ENABLE;
+	if (mbus->hw_io_coherency)
+		ctrl |= WIN_CTRL_SYNCBARRIER;
 
 	writel(base & WIN_BASE_LOW, addr + WIN_BASE_OFF);
 	writel(ctrl, addr + WIN_CTRL_OFF);


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