Re: [PATCH V4 3/3] ARM: dts: Add pcie controller node for SamsungEXYNOS5440 SoC

From: Jingoo Han
Date: Thu Jun 13 2013 - 01:34:22 EST


On Wednesday, June 12, 2013 7:56 PM, Arnd Bergmann wrote:
>
> Thanks for the update! A few comments again:
>
> On Wednesday 12 June 2013 19:20:00 Jingoo Han wrote:
> >
> > diff --git a/arch/arm/boot/dts/exynos5440-ssdk5440.dts b/arch/arm/boot/dts/exynos5440-ssdk5440.dts
> > index d55042b..efe7d39 100644
> > --- a/arch/arm/boot/dts/exynos5440-ssdk5440.dts
> > +++ b/arch/arm/boot/dts/exynos5440-ssdk5440.dts
> > @@ -30,4 +30,12 @@
> > clock-frequency = <50000000>;
> > };
> > };
> > +
> > + pcie0@40000000 {
> > + reset-gpio = <5>;
> > + };
> > +
> > + pcie1@60000000 {
> > + reset-gpio = <22>;
> > + };
> > };
>
> As mentioned before, please use the gpio binding to pass gpio numbers.

OK, I will use gpio binding.

>
> > diff --git a/arch/arm/boot/dts/exynos5440.dtsi b/arch/arm/boot/dts/exynos5440.dtsi
> > index f6b1c89..2c15f9d 100644
> > --- a/arch/arm/boot/dts/exynos5440.dtsi
> > +++ b/arch/arm/boot/dts/exynos5440.dtsi
> > @@ -216,4 +216,42 @@
> > clock-names = "rtc";
> > status = "disabled";
> > };
> > +
> > + pcie0@0x290000 {
> > + compatible = "samsung,exynos5440-pcie";
> > + reg = <0x290000 0x1000
> > + 0x270000 0x1000
> > + 0x271000 0x40>;
> > + interrupts = <0 20 0>, <0 21 0>, <0 22 0>;
> > + clocks = <&clock 28>, <&clock 27>;
> > + clock-names = "pcie", "pcie_bus";
> > + #address-cells = >;
> > + #size-cells = <2>;
> > + device_type = "pci";
> > + ranges = <0x00000800 0 0x40000000 0x40000000 0 0x00200000 /* configuration space */
> > + 0x81000000 0 0 0x40200000 0 0x00010000 /* downstream I/O */
> > + 0x82000000 0 0x40210000 0x40210000 0 0x10000000>; /* non-prefetchable memory */
>
> I think you did not reply to my question regarding the size of the
> memory space. Does it extend from 0x40210000 to 0x50210000,
> or from 0x40210000 to 0x50000000. You probably meant the latter
> but wrote the former. If not, please add a comment for clarification.

OK, I see.
It extends to 0x60000000. I will modify it.

>
> > + #interrupt-cells = <1>;
> > + interrupt-map-mask = <0 0 0 0>;
> > + interrupt-map = <0x0 0 &gic 53>;
> > + };
>
> So all PCI IntA interrupts are mapped to a single gic interrupt? That
> sounds like a bottleneck when you have a lot of devices on the bus.
> Do you have MSI support?

INTA, INTB, INTC, and INTD are mapped to a single gic interrupt.
Exynos5440 PCIe has MSI support; however, MSI support patch will
be posted later.

>
> Arnd

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/