[U-Boot] [PATCH 2/2] sunxi: Enable MMC new mode for A83T

[Maxime Ripard]

On Mon, Aug 28, 2017 at 02:30:23PM +0530, Jagan Teki wrote:
> On Mon, Aug 28, 2017 at 2:15 PM, Maxime Ripard
> <maxime.ripard at free-electrons.com> wrote:
> > On Mon, Aug 28, 2017 at 04:12:15PM +0800, Chen-Yu Tsai wrote:
> >> On Mon, Aug 28, 2017 at 4:05 PM, Jagan Teki <jagannadh.teki at gmail.com> wrote:
> >> > On Mon, Aug 28, 2017 at 12:29 PM, Maxime Ripard
> >> > <maxime.ripard at free-electrons.com> wrote:
> >> >> Hi Jagan,
> >> >>
> >> >> On Sat, Aug 26, 2017 at 12:11:23PM +0530, Jagan Teki wrote:
> >> >>> On Wed, Aug 23, 2017 at 3:33 PM, Maxime Ripard
> >> >>> <maxime.ripard at free-electrons.com> wrote:
> >> >>> > The eMMC controller for the A83T uses the new operating mode. Enable it.
> >> >>> >
> >> >>> > Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>
> >> >>>
> >> >>> Reviewed-by: Jagan Teki <jagan at openedev.com>
> >> >>
> >> >> I think both these patches should be merged in the upcoming
> >> >> release. It's a fix for a usecase that already exists (we already
> >> >> enable the eMMC on A83T), and it's unusable on some boards without it.
> >> >
> >> > But none of A83T boards were not enable eMMC yet? even sun8i-a83t.dtsi
> >> > still need to add node. May be we can wait once all add?
> >>
> >> The sunxi-mmc driver does not use the device tree.
> >>
> >> One only needs to set CONFIG_MMC_SUNXI_SLOT_EXTRA=2 to use the eMMC.
> >> And yes, eMMC is broken on some boards unless the new timing mode is
> >> used.
> >
> > And the support is broken until "mmc: sunxi: fix legacy MMC
> > initialisation" in my other serie is applied.
> 
> With these patches, eMMC detected BPI-M3. But none of A83T boards have
> CONFIG_MMC_SUNXI_SLOT_EXTRA=2 So it's better to take this once boards
> added.

That argument doesn't really stand, any user is able to modify the
configuration themself, and experience that breakage.

The fact that this is not enabled by default just make it less
exposed, but it's still a bug that can be encountered today in a
real-life situation.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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