From: Frank Wunderlich <frank-w@public-files.de>
To: Peter Geis <pgwipeout@gmail.com>
Cc: "Bjorn Helgaas" <helgaas@kernel.org>,
"Rob Herring" <robh+dt@kernel.org>,
"Frank Wunderlich" <linux@fw-web.de>,
"open list:ARM/Rockchip SoC..."
<linux-rockchip@lists.infradead.org>,
"Kishon Vijay Abraham I" <kishon@ti.com>,
"Vinod Koul" <vkoul@kernel.org>,
"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
"Heiko Stuebner" <heiko@sntech.de>,
"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
"Krzysztof Wilczyński" <kw@linux.com>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Philipp Zabel" <p.zabel@pengutronix.de>,
"Johan Jonker" <jbx6244@gmail.com>,
"Michael Riesch" <michael.riesch@wolfvision.net>,
"open list:GENERIC PHY FRAMEWORK" <linux-phy@lists.infradead.org>,
devicetree <devicetree@vger.kernel.org>,
arm-mail-list <linux-arm-kernel@lists.infradead.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
PCI <linux-pci@vger.kernel.org>
Subject: Aw: Re: Re: [RFC/RFT 4/6] PCI: rockchip-dwc: add pcie bifurcation
Date: Thu, 21 Apr 2022 17:41:39 +0200 [thread overview]
Message-ID: <trinity-1c858470-8354-4ecd-ace7-a6e437cb5923-1650555699148@3c-app-gmx-bap38> (raw)
In-Reply-To: <CAMdYzYpydGyQZT2n9Tf+ccQMLHzfhOgoyamMgspQDcjzm3Umdg@mail.gmail.com>
> Gesendet: Montag, 18. April 2022 um 18:17 Uhr
> Von: "Peter Geis" <pgwipeout@gmail.com>
> > On Sun, Apr 17, 2022 at 11:08:02AM +0200, Frank Wunderlich wrote:
> > > > On Sat, Apr 16, 2022 at 03:54:56PM +0200, Frank Wunderlich wrote:
> > > > > From: Frank Wunderlich <frank-w@public-files.de>
> > > > >
> > > > > PCIe Lanes can be split to 2 slots with bifurcation.
> > > > > Add support for this in existing pcie driver.
> >
> > > > Is the "rockchip,bifurcation" DT property something that should be
> > > > generalized so it's not rockchip-specific? Other controllers are
> > > > likely to support similar functionality.
> > >
> > > I do not know if other controllers support similar functionality,
> > > but i ack a property without vendor prefix is better. Should i use
> > > "bifurcation" as name or do you think about a different name which
> > > is more generic?
> >
> > Really a question for Rob about what name would be good and where it
> > should go.
>
> It might be good to define this as a lane map.
> In the Rockchip implementation it's only 2+0 or 1+1, but that isn't
> guaranteed if this is made into a standard definition.
> So perhaps:
> pcie-bifurcation-map = <0>, <1>;
> pcie-bifurcation-map = <1>;
> pcie-bifurcation-map = <4>, <5>, <6>, <7>;
how about a lane-map like this (from controllers point of view):
rockchip with only 2 lanes (like rk3568):
controller 1:
lane-map = <1 0>;
controller 2:
lane-map = <0 1>;
here bifurcation is set if a controller does not aquire all lanes.Afaik rk3568 cannot select specific lanes so i end up with bifurcation = true/false (an aggregation-mode on phy) again. but it makes dts-property more usable for other devices/SoC.
this contains the maximum of lanes and as mask the lanes to take by the current controller. It is scalable to support more pcie-lanes (x2 x4 x8)
example for 2 controllers with PCIe x4 (with 8 lanes available):
lane-map=<0 0 0 0 1 1 1 1>;
lane-map=<1 1 1 1 0 0 0 0>;
of course they can be mixed, if driver supports this.
lane-map=<0 1 0 1 0 1 0 1>;
lane-map=<1 0 1 0 1 0 1 0>;
such lane-map is more flexible
regards Frank
next prev parent reply other threads:[~2022-04-21 15:43 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-16 13:54 [RFC/RFT 0/6] RK3568 PCIe V3 support Frank Wunderlich
2022-04-16 13:54 ` [RFC/RFT 1/6] dt-bindings: phy: rockchip: add pcie3 phy Frank Wunderlich
2022-04-18 15:52 ` Krzysztof Kozlowski
2022-04-19 17:49 ` Aw: " Frank Wunderlich
2022-04-19 19:43 ` Krzysztof Kozlowski
2022-04-19 20:36 ` Aw: " Frank Wunderlich
2022-04-19 20:48 ` Krzysztof Kozlowski
2022-04-16 13:54 ` [RFC/RFT 2/6] dt-bindings: soc: grf: add pcie30-{phy,pipe}-grf Frank Wunderlich
2022-04-18 15:54 ` Krzysztof Kozlowski
2022-04-19 17:29 ` Aw: " Frank Wunderlich
2022-04-19 19:40 ` Krzysztof Kozlowski
2022-04-20 13:04 ` Aw: " Frank Wunderlich
2022-04-16 13:54 ` [RFC/RFT 3/6] phy: rockchip: Support pcie v3 Frank Wunderlich
2022-04-18 10:38 ` Vinod Koul
2022-04-18 15:57 ` Krzysztof Kozlowski
2022-04-20 7:29 ` Philipp Zabel
2022-04-16 13:54 ` [RFC/RFT 4/6] PCI: rockchip-dwc: add pcie bifurcation Frank Wunderlich
2022-04-16 23:30 ` Bjorn Helgaas
2022-04-17 9:08 ` Aw: " Frank Wunderlich
2022-04-18 15:53 ` Bjorn Helgaas
2022-04-18 16:17 ` Peter Geis
2022-04-21 15:41 ` Frank Wunderlich [this message]
2022-04-16 13:54 ` [RFC/RFT 5/6] arm64: dts: rockchip: rk3568: Add PCIe v3 nodes Frank Wunderlich
2022-04-16 13:54 ` [RFC/RFT 6/6] arm64: dts: rockchip: Add PCIe v3 nodes to BPI-R2-Pro Frank Wunderlich
2022-04-18 15:57 ` Krzysztof Kozlowski
2022-05-11 19:26 ` [RFC/RFT 0/6] RK3568 PCIe V3 support Piotr Oniszczuk
2022-05-11 20:10 ` Frank Wunderlich
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