Messages in this thread | | | From | Leo Li <> | Subject | RE: [PATCH v3 1/8] arm64: dts: ls1028a: Add PCIe EP nodes | Date | Wed, 13 Apr 2022 18:38:54 +0000 |
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> -----Original Message----- > From: Vladimir Oltean <olteanv@gmail.com> > Sent: Wednesday, April 13, 2022 1:22 PM > To: Leo Li <leoyang.li@nxp.com> > Cc: Z.Q. Hou <zhiqiang.hou@nxp.com>; Shawn Guo > <shawnguo@kernel.org>; linux-arm-kernel@lists.infradead.org; linux- > kernel@vger.kernel.org; Xiaowei Bao <xiaowei.bao@nxp.com> > Subject: Re: [PATCH v3 1/8] arm64: dts: ls1028a: Add PCIe EP nodes > > On Wed, Apr 13, 2022 at 06:03:37PM +0000, Leo Li wrote: > > > arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi:631.23-656.5: Warning > > > (unique_unit_address): /soc/pcie@3400000: duplicate unit-address > > > (also used in node /soc/pcie-ep@3400000) > > > arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi:670.23-695.5: Warning > > > (unique_unit_address): /soc/pcie@3500000: duplicate unit-address > > > (also used in node /soc/pcie-ep@3500000) > > > > This would be a common problem for all the layerscape PCIe controller. > > The controller can either work in RC mode or EP mode. The current > > binding of the controller defined two compatibles, one for RC and one > > for EP. Therefore the SoC dtsi will have two nodes with the same unit > > address one for EP one for RC. Fixing this probably requires > > comprehensive updates to the binding which breaks backward > > compatibility. > > So we have to live with these warnings forever now? > > How are the PCIe controllers configured for RC or EP mode? Via RCW? > Is dynamic configuration possible?
Yes. It is configured via RCW on reset. I don't think it can be changed at runtime.
> > Can't U-Boot detect the operating mode from the RCW and fix up the > compatible string in case the controller is in endpoint mode?
I believe the u-boot is already updating the node status to enable the correct one. But it might be confusing to change the compatible and a bunch of other properties at boot time.
Regards, Leo
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