On Tue, Mar 29, 2016 at 8:11 AM, Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx> wrote: > On some SOCs PORTS_IMPL register value is never programmed by the BIOS s/BIOS/firmware/ You do plan to fix this in your firmware/bootloader, too, right? > and left at zero value. Which means that no sata ports are avaiable for > software. AHCI driver used to cope up with this by fabricating the > port_map if the PORTS_IMPL register is read zero, but recent patch > broke this workaround as zero value was valid for nvme disks. s/nvme/NVMe/ > > This patch adds ports-implemented dt bindings as workaround for this issue s/dt/DT/ > in a way that DT can dictate the port_map incase where the SOCs does not > program it already. port_map is a Linux term. ...can override the PORTS_IMPL register in cases where the firmware did not program it already. > > Fixes: 566d1827df2e ("libata: disable forced PORTS_IMPL for >= AHCI 1.3) > Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx> > --- > Documentation/devicetree/bindings/ata/ahci-platform.txt | 11 +++++++++++ > drivers/ata/ahci_platform.c | 4 ++++ > 2 files changed, 15 insertions(+) > > diff --git a/Documentation/devicetree/bindings/ata/ahci-platform.txt b/Documentation/devicetree/bindings/ata/ahci-platform.txt > index 30df832..8165db3 100644 > --- a/Documentation/devicetree/bindings/ata/ahci-platform.txt > +++ b/Documentation/devicetree/bindings/ata/ahci-platform.txt > @@ -32,6 +32,10 @@ Optional properties: > - target-supply : regulator for SATA target power > - phys : reference to the SATA PHY node > - phy-names : must be "sata-phy" > +- ports-implemented : Mask that indicates which ports that the HBA supports > + are available for software to use. Useful if PORTS_IMPL > + is not programmed by the BIOS, which is true with > + some embedded SOC's. > > Required properties when using sub-nodes: > - #address-cells : number of cells to encode an address > @@ -59,6 +63,13 @@ Examples: > target-supply = <®_ahci_5v>; > }; > > + sata0: sata@29000000 { /* Qualcomm APQ8064 */ Do you really need another example just for this? > + compatible = "generic-ahci"; Where's your chip specific compatible string? You would not require a DT update to fix this if you had that. > + reg = <0x29000000 0x180>; > + interrupts = <GIC_SPI 209 IRQ_TYPE_NONE>; > + ports-implemented = <0x1>; > + }; > + > With sub-nodes: > sata@f7e90000 { > compatible = "marvell,berlin2q-achi", "generic-ahci"; > diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c > index 4044233..ec8db80 100644 > --- a/drivers/ata/ahci_platform.c > +++ b/drivers/ata/ahci_platform.c > @@ -42,6 +42,7 @@ static int ahci_probe(struct platform_device *pdev) > struct device *dev = &pdev->dev; > struct ahci_host_priv *hpriv; > int rc; > + u32 ports_impl; > > hpriv = ahci_platform_get_resources(pdev); > if (IS_ERR(hpriv)) > @@ -51,6 +52,9 @@ static int ahci_probe(struct platform_device *pdev) > if (rc) > return rc; > > + of_property_read_u32(dev->of_node, > + "ports-implemented", &hpriv->force_port_map); > + > if (of_device_is_compatible(dev->of_node, "hisilicon,hisi-ahci")) > hpriv->flags |= AHCI_HFLAG_NO_FBS | AHCI_HFLAG_NO_NCQ; > > -- > 2.5.0 > -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html