On Wed, Sep 17, 2014 at 11:55 PM, Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote: > On Tue, Sep 16, 2014 at 10:13:27PM +0800, Chen-Yu Tsai wrote: >> >> + /* >> >> + * sun8i variant requires us to toggle an undocumented register, >> >> + * as seen in Allwinner's SDK. >> > >> > The BSP I have has this: >> > >> > static void sunxi_dma_hw_init(struct sunxi_dmadev *dev) >> > { >> > struct sunxi_dmadev *sunxi_dev = dev; >> > >> > clk_prepare_enable(sunxi_dev->ahb_clk); >> > #ifdef CONFIG_ARCH_SUN8IW3 >> > writel(0x04, sunxi_dev->base + DMA_GATE); >> > #endif >> > } >> > >> > /* All is ok, and open the clock */ >> > sunxi_dma_hw_init(sunxi_dev); >> > >> > So I guess we can say that it's not that undocumented :) >> >> That's right. I meant undocumented in the user manual. >> I did reference the SDK in the comment, didn't I? :) > > So something like > > writel(DMA_GATE_ENABLE, base->DMA_GATE_REG) wouldn't be too far off :) Sure. Will also update the comment to reflect the naming. ChenYu -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html