RE: Re: [PATCH 1/2] ARM: dts: imx6qp-sabresd: enable pcie

From: Richard Zhu
Date: Mon Aug 31 2020 - 22:51:53 EST


> -----Original Message-----
> From: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> Sent: 2020年7月21日 16:16
> To: Richard Zhu <hongxing.zhu@xxxxxxx>; bhelgaas@xxxxxxxxxx;
> shawnguo@xxxxxxxxxx; festevam@xxxxxxxxx
> Cc: linux-pci@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>;
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> kernel@xxxxxxxxxxxxxx
> Subject: [EXT] Re: [PATCH 1/2] ARM: dts: imx6qp-sabresd: enable pcie
>
> Caution: EXT Email
>
> Am Dienstag, den 21.07.2020, 15:44 +0800 schrieb Richard Zhu:
> > Add one regulator, used to power up the external oscillator, and
> > enable PCIe on iMX6QP SABRESD board.
>
> That's not the right thing to do. If there is an external oscillator, which requires a
> power supply then the oscillator should have its own clock DT node (it's a
> separate device after all) and this node needs to control the regulator.
>
> This has nothing to do with the PCIe controller, which only cares about the clock
> being provided.
>
To be simple, and easy to maintain. How about to set the vgen3 always on in this case?

Best Regards
Richard Zhu

> Regards,
> Lucas
>
> > Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
> > ---
> > arch/arm/boot/dts/imx6qp-sabresd.dts | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/arm/boot/dts/imx6qp-sabresd.dts
> > b/arch/arm/boot/dts/imx6qp-sabresd.dts
> > index 480e73183f6b..cd8a1f610427 100644
> > --- a/arch/arm/boot/dts/imx6qp-sabresd.dts
> > +++ b/arch/arm/boot/dts/imx6qp-sabresd.dts
> > @@ -51,7 +51,8 @@
> > };
> >
> > &pcie {
> > - status = "disabled";
> > + vepdev-supply = <&vgen3_reg>;
> > + status = "okay";
> > };
> >
> > &sata {