Hi Andrew, Thanks a lot for your review! Regards, Zhiqiang > -----Original Message----- > From: Andrew Murray <andrew.murray@xxxxxxx> > Sent: 2019年8月12日 16:35 > To: Z.q. Hou <zhiqiang.hou@xxxxxxx> > Cc: linux-pci@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; gustavo.pimentel@xxxxxxxxxxxx; > jingoohan1@xxxxxxxxx; bhelgaas@xxxxxxxxxx; robh+dt@xxxxxxxxxx; > mark.rutland@xxxxxxx; shawnguo@xxxxxxxxxx; Leo Li > <leoyang.li@xxxxxxx>; lorenzo.pieralisi@xxxxxxx; M.h. Lian > <minghuan.lian@xxxxxxx> > Subject: Re: [PATCH 3/4] ARM: dts: ls1021a: Remove num-lanes property > from PCIe nodes > > On Mon, Aug 12, 2019 at 04:22:27AM +0000, Z.q. Hou wrote: > > From: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx> > > > > On FSL Layerscape SoCs, the number of lanes assigned to PCIe > > controller is not fixed, it is determined by the selected SerDes > > protocol in the RCW (Reset Configuration Word), and the PCIe link > > training is completed automatically base on the selected SerDes > > protocol, and the link width set-up is updated by hardware. So the > > num-lanes is not needed to specify the link width. > > > > The current num-lanes indicates the max lanes PCIe controller can > > support up to, instead of the lanes assigned to the PCIe controller. > > This can result in PCIe link training fail after hot-reset. So remove > > the num-lanes to avoid set-up to incorrect link width. > > > > Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx> > > --- > > arch/arm/boot/dts/ls1021a.dtsi | 2 -- > > 1 file changed, 2 deletions(-) > > > > diff --git a/arch/arm/boot/dts/ls1021a.dtsi > > b/arch/arm/boot/dts/ls1021a.dtsi index 464df4290ffc..2f6977ada447 > > 100644 > > --- a/arch/arm/boot/dts/ls1021a.dtsi > > +++ b/arch/arm/boot/dts/ls1021a.dtsi > > @@ -874,7 +874,6 @@ > > #address-cells = <3>; > > #size-cells = <2>; > > device_type = "pci"; > > - num-lanes = <4>; > > num-viewport = <6>; > > bus-range = <0x0 0xff>; > > ranges = <0x81000000 0x0 0x00000000 0x40 0x00010000 0x0 > 0x00010000 /* downstream I/O */ > > @@ -899,7 +898,6 @@ > > #address-cells = <3>; > > #size-cells = <2>; > > device_type = "pci"; > > - num-lanes = <4>; > > num-viewport = <6>; > > bus-range = <0x0 0xff>; > > ranges = <0x81000000 0x0 0x00000000 0x48 0x00010000 0x0 > 0x00010000 /* downstream I/O */ > > Reviewed-by: Andrew Murray <andrew.murray@xxxxxxx> > > > -- > > 2.17.1 > >
