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> Cc: <stable@xxxxxxxxxxxxxxx> # v4.0+ Fixes: a0b5cd4ac2d6 ("bus: mvebu-mbus: use automatic I/O synchronization barriers") --- drivers/bus/mvebu-mbus.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/bus/mvebu-mbus.c b/drivers/bus/mvebu-mbus.c index fb9ec62..7fa4510 100644 --- 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(struct mvebu_mbus_state *mbus, 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); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html