RE: [EXT] Re: [PATCH 02/11] dts: mvebu: Update A8K AP806 SDHCI settings

[Kostya Porotchkin]

> -----Original Message-----
> From: Russell King - ARM Linux admin <linux@xxxxxxxxxxxxxxx>
> Sent: Wednesday, February 3, 2021 16:39
> To: Kostya Porotchkin <kostap@xxxxxxxxxxx>
> Cc: Baruch Siach <baruch@xxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; andrew@xxxxxxx; jaz@xxxxxxxxxxxx;
> gregory.clement@xxxxxxxxxxx; Nadav Haklai <nadavh@xxxxxxxxxxx>;
> robh+dt@xxxxxxxxxx; Stefan Chulski <stefanc@xxxxxxxxxxx>;
> mw@xxxxxxxxxxxx; Ben Peled <bpeled@xxxxxxxxxxx>;
> sebastian.hesselbarth@xxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [EXT] Re: [PATCH 02/11] dts: mvebu: Update A8K AP806 SDHCI
> settings
> 
> On Wed, Feb 03, 2021 at 02:37:22PM +0000, Kostya Porotchkin wrote:
> > Hi, Baruch,
> >
> > > -----Original Message-----
> > > From: Baruch Siach <baruch@xxxxxxxxxx>
> > > Sent: Wednesday, February 3, 2021 15:59
> > > To: Kostya Porotchkin <kostap@xxxxxxxxxxx>
> > > Cc: linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx;
> > > andrew@xxxxxxx; jaz@xxxxxxxxxxxx; gregory.clement@xxxxxxxxxxx;
> > > linux@xxxxxxxxxxxxxxx; Nadav Haklai <nadavh@xxxxxxxxxxx>;
> > > robh+dt@xxxxxxxxxx; Stefan Chulski <stefanc@xxxxxxxxxxx>;
> > > mw@xxxxxxxxxxxx; Ben Peled <bpeled@xxxxxxxxxxx>;
> > > sebastian.hesselbarth@xxxxxxxxx;
> > > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> > > Subject: [EXT] Re: [PATCH 02/11] dts: mvebu: Update A8K AP806 SDHCI
> > > settings
> > >
> > > External Email
> > >
> > > --------------------------------------------------------------------
> > > --
> > > Hi Konstantin,
> > >
> > > On Wed, Feb 03 2021, kostap@xxxxxxxxxxx wrote:
> > > > From: Konstantin Porotchkin <kostap@xxxxxxxxxxx>
> > > >
> > > > Update the settings for AP806 SDHCI interface according to latest
> > > > Xenon drivers changes.
> > > > - no need to select the PHY slow mode anymore
> > >
> > > Why? Has anything changed since the introduction of
> > > marvell,xenon-phy-slow- mode?
> > [KP] AP806 B0, AP807 and later do not need the "slow mode" set by the
> default.
> > The HWE-7296210 errata is not applicable to these components and they
> > are able to run  AP SDHCI in HS400 8-bit mode.
> 
> So what about all those people, such as me, who have A0 silicon on their
> Macchiatobin boards?
> 
> You can't just go around removing DT properties like this.
> 
[KP] So for older systems this "slow mode" parameter could be set on the board level.
When it is set in ap80x,dtsi file it downgrades all systems to HS-SDR52, even if they support HS400 on AP side.
MacchiatoBIN AP eMMC is connected to 3.3v regulator and has "no-1-8-v" flag set, so it should remain in low speed anyway.

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