From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liviu Dudau Subject: Re: [PATCH 3/6] pci, thunder: Add PCIe host controller devicetree bindings Date: Tue, 7 Oct 2014 16:01:49 +0100 Message-ID: <20141007150149.GW4652@e106497-lin.cambridge.arm.com> References: <1411573068-12952-1-git-send-email-rric@kernel.org> <1411573068-12952-4-git-send-email-rric@kernel.org> <3082935.e3X4GsVUDn@wuerfel> <20141007142744.GE31556@rric.localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20141007142744.GE31556-vWBEXY7mpu73kLQC+b9v0A@public.gmane.org> Content-Disposition: inline Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Robert Richter Cc: Arnd Bergmann , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , Robert Richter , Bjorn Helgaas , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Catalin Marinas , Will Deacon , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Sunil Goutham List-Id: devicetree@vger.kernel.org On Tue, Oct 07, 2014 at 03:27:44PM +0100, Robert Richter wrote: > On 24.09.14 18:06:04, Arnd Bergmann wrote: > > > + compatible =3D "cavium,thunder-pcie"; > > > + device_type =3D "pci"; > > > + msi-parent =3D <&its>; > > > + bus-range =3D <0 255>; > > > + #size-cells =3D <2>; > > > + #address-cells =3D <3>; > > > + reg =3D <0x8480 0x00000000 0 0x10000000>; /* Con= figuration space */ > > > + ranges =3D <0x03000000 0x8010 0x00000000 0x8010 0= x00000000 0x70 0x00000000>, /* mem ranges */ > > > + <0x03000000 0x8300 0x00000000 0x8300 0x00= 000000 0x80 0x00000000>, > > > + <0x03000000 0x87e0 0x00000000 0x87e0 0x00= 000000 0x01 0x00000000>; > > > + }; > >=20 > > If you claim the entire 0-255 bus range, I think you should also > > specify a domain, otherwise it's not predictable which domain you > > get. >=20 > Liviu's code assigns a unique id to the domain if missing, see > of_pci_get_domain_nr(). So I don't think we need to add a "pci-domain= " > property here. Not anymore! That function is gone in v12 onwards. What is in -next has a new function called of_get_pci_domain_nr() (slight name change) but that only gets the value set in the "linux,pci-domain" property of the device node. It is the choice of the host bridge driver to use that function or to use pci_get_new_domain_nr() which *does* generate an unique id every time it gets called. >=20 > Liviu's DT implementation that assigns a unique number differs a bit > from ACPI which states: "If _SEG [aka domain number] does not exist, > OSPM assumes that all PCI bus segments are in PCI Segment Group 0." >=20 > Maybe of_pci_get_domain_nr() should be similar to ACPI. If there are > multiple root bridges, the "pci-domain" property could be forced > instead. Indeed. But the enforcing is left as an exercise to the host bridge implementor for the moment. Best regards, Liviu >=20 > -Robert >=20 --=20 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- =C2=AF\_(=E3=83=84)_/=C2=AF -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html