Commit c4b4b732 authored Nov 22, 2012 by Thomas Petazzoni

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>

parent 9f3410ff

drivers/dma/mv_xor.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -1240,6 +1240,8 @@ mv_xor_conf_mbus_windows(struct mv_xor_device *xordev,

		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)

drivers/dma/mv_xor.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -53,6 +53,7 @@
		#define WINDOW_SIZE(w) (0x270 + ((w) << 2))
		#define WINDOW_REMAP_HIGH(w) (0x290 + ((w) << 2))
		#define WINDOW_BAR_ENABLE(chan) (0x240 + ((chan) << 2))
		#define WINDOW_OVERRIDE_CTRL(chan) (0x2A0 + ((chan) << 2))

		struct mv_xor_device {
		void __iomem *xor_base;