dma: mv_xor: clear the window override control registers
The XOR channels on Marvell SoCs have a Window Override Control
register that allow to do some fancy things with addresses. Those
features are not used by the driver, but some U-Boot versions anyway
modify those registers.
For some reason, the U-Boot on OpenBlocks AX3-4 was setting an invalid
value in those registers when the addition 2 GB DRAM chip was plugged
into the board, causing the XOR driver to fail in using the XOR
engines.
By setting those registers to 0 during the driver initialization, we
ensure that the registers are configured according with the driver
operation model.
Thanks to Lior Amsalem <alior@marvell.com> for his help in debugging
this problem.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
index f450fe8..2c69b89 100644
--- a/drivers/dma/mv_xor.c
+++ b/drivers/dma/mv_xor.c
@@ -1240,6 +1240,8 @@
writel(win_enable, base + WINDOW_BAR_ENABLE(0));
writel(win_enable, base + WINDOW_BAR_ENABLE(1));
+ writel(0, base + WINDOW_OVERRIDE_CTRL(0));
+ writel(0, base + WINDOW_OVERRIDE_CTRL(1));
}
static int __devinit mv_xor_probe(struct platform_device *pdev)