From: "Clément Péron" <peron.clem@gmail.com>
To: Maxime Ripard <maxime@cerno.tech>
Cc: Rob Herring <robh+dt@kernel.org>, Chen-Yu Tsai <wens@csie.org>,
devicetree <devicetree@vger.kernel.org>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] arm64: dts: allwinner: h6: add eMMC voltage property for Beelink GS1
Date: Mon, 5 Oct 2020 20:47:19 +0200 [thread overview]
Message-ID: <CAJiuCcfydz4GS3fUTampBLkDC4f6xVWmRpSRJ55TiDStdRCFmA@mail.gmail.com> (raw)
In-Reply-To: <20201005092145.wdu4m4pwxydv76ou@gilmour.lan>
Hi Maxime,
On Mon, 5 Oct 2020 at 11:21, Maxime Ripard <maxime@cerno.tech> wrote:
>
> Hi Clément,
>
> On Sat, Oct 03, 2020 at 11:20:01AM +0200, Clément Péron wrote:
> > Sunxi MMC driver can't distinguish at runtime what's the I/O voltage
> > for HS200 mode.
>
> Unfortunately, that's not true (or at least, that's not related to your patch).
>
> > Add a property in the device-tree to notify MMC core about this
> > configuration.
> >
> > Fixes: 089bee8dd119 ("arm64: dts: allwinner: h6: Introduce Beelink GS1 board")
> > Signed-off-by: Clément Péron <peron.clem@gmail.com>
> > ---
> > arch/arm64/boot/dts/allwinner/sun50i-h6-beelink-gs1.dts | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm64/boot/dts/allwinner/sun50i-h6-beelink-gs1.dts b/arch/arm64/boot/dts/allwinner/sun50i-h6-beelink-gs1.dts
> > index 049c21718846..3f20d2c9bbbb 100644
> > --- a/arch/arm64/boot/dts/allwinner/sun50i-h6-beelink-gs1.dts
> > +++ b/arch/arm64/boot/dts/allwinner/sun50i-h6-beelink-gs1.dts
> > @@ -145,6 +145,7 @@ &mmc2 {
> > vqmmc-supply = <®_bldo2>;
> > non-removable;
> > cap-mmc-hw-reset;
> > + mmc-hs200-1_8v;
> > bus-width = <8>;
> > status = "okay";
> > };
>
> I'm not really sure what you're trying to fix here, but as far as MMC
> goes, eMMC's can support io voltage of 3.3, 1.8 and 1.2V. Modes up until
> HS DDR (50MHz in DDR) will use an IO voltage of 3.3V, higher speed modes
> (HS200 and HS400) supporting 1.8V and 1.2V.
Some users report that the eMMC is not working properly on their
Beelink GS1 boards.
>
> The mmc-hs200-1_8v property states that the MMC controller supports the
> HS200 mode at 1.8V. Now, I can only assume that since BLDO2 is set up at
> 1.8V then otherwise, the MMC core will rightfully decide to use the
> highest supported mode. In this case, since the driver sets it, it would
> be HS-DDR at 3.3V, which won't work with that fixed regulator.
>
> I can only assume that enabling HS200 at 1.8V only fixes the issue you
> have because otherwise it would use HS-DDR at 3.3V, ie not actually
> fixing the issue but sweeping it under the rug.
>
> Trying to add mmc-ddr-1_8v would be a good idea
Thanks for the explanation, this is indeed the correct one.
So It looks like the SDIO controller has an issue on some boards when
using HS-DDR mode.
Is this patch acceptable with the proper commit log?
It looks like the same issue is happening on A64 Pinebook board.
Thanks
Clement
>
> Maxime
next prev parent reply other threads:[~2020-10-05 18:47 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-03 9:20 [PATCH v2] arm64: dts: allwinner: h6: add eMMC voltage property for Beelink GS1 Clément Péron
2020-10-05 9:21 ` Maxime Ripard
2020-10-05 18:47 ` Clément Péron [this message]
2020-10-08 15:10 ` Maxime Ripard
2020-10-08 20:00 ` Clément Péron
2020-10-09 7:36 ` Maxime Ripard
2020-10-13 21:27 ` Jernej Škrabec
2020-10-15 9:35 ` Maxime Ripard
2020-10-15 21:09 ` Jernej Škrabec
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