Hello, On Fri, Oct 30, 2015 at 11:01:16PM +0900, Jaedon Shin wrote: > +static void brcm_sata_quirks(struct platform_device *pdev, > + struct brcm_ahci_priv *priv) > +{ > + if (priv->quirks & BRCM_AHCI_QUIRK_NONCQ) { > + void __iomem *ctrl = priv->top_ctrl + SATA_TOP_CTRL_BUS_CTRL; > + void __iomem *ahci; > + struct resource *res; > + u32 reg; > + > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, > + "ahci"); > + ahci = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(ahci)) > + return; > + > + reg = brcm_sata_readreg(ctrl); > + reg |= OVERRIDE_HWINIT; > + brcm_sata_writereg(reg, ctrl); > + > + /* Clear out the NCQ bit so the AHCI driver will not issue > + * FPDMA/NCQ commands. > + */ > + reg = readl(ahci + HOST_CAP); > + reg &= ~HOST_CAP_NCQ; > + writel(reg, ahci + HOST_CAP); > + > + reg = brcm_sata_readreg(ctrl); > + reg &= ~OVERRIDE_HWINIT; > + brcm_sata_writereg(reg, ctrl); > + > + devm_iounmap(&pdev->dev, ahci); > + devm_release_mem_region(&pdev->dev, res->start, > + resource_size(res)); > + } > +} Does the controller actually need HOST_CAP_NCQ bit turned off to work correctly? If the only thing necessary is the host not issuing NCQ commands, setting AHCI_HFLAG_NO_NCQ should do. > static void brcm_sata_init(struct brcm_ahci_priv *priv) > { > /* Configure endianness */ > @@ -256,6 +297,11 @@ static int brcm_ahci_probe(struct platform_device *pdev) > if (IS_ERR(priv->top_ctrl)) > return PTR_ERR(priv->top_ctrl); > > + if (of_device_is_compatible(dev->of_node, "brcm,bcm7425-ahci")) > + priv->quirks |= BRCM_AHCI_QUIRK_NONCQ; > + > + brcm_sata_quirks(pdev, priv); What's the point of "branch - set a bit - test the bit" sequence? Just do if (of_device_is_compatiable(...)) brcm_ahci_disable_ncq(...); Thanks. -- tejun -- 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