[PATCH] sunxi-nand: fix the PIO instead of DMA implementation

[Markus Hoffrogge]

Hi Miquel, hi Maxime,

could you probably run a test on a newer Allwinner SOC - like e.g.
SUNI8, SUNI9, SUNI50 or newer, since I can test it on a SUNI7 (A20)
board only?

The only aspect that makes me wonder is, that it did work on your
hardware before at all.

Maybe this is, since that NFC_CTL_RAM_METHOD flag does not matter on
newer SOC, if the DMA channel is not enabled for the NFC.

Markus
Am Do., 30. Juni 2022 um 09:31 Uhr schrieb Maxime Ripard <maxime at cerno.tech>:
>
> On Thu, Jun 30, 2022 at 09:13:22AM +0200, Miquel Raynal wrote:
> > Hi Markus,
> >
> > + Maxime, for the record :)
> >
> > mhoffrogge at gmail.com wrote on Thu, 30 Jun 2022 01:26:39 +0200:
> >
> > > The sunxi nand SPL loader was broken at least for SUN4I,
> > > SUN5I and SUN7I SOCs since the implementation change
> > > from DMA to PIO usage - commit 6ddbb1e.
> > >
> > > Root cause for this issue is the NFC control flag NFC_CTL_RAM_METHOD
> > > being set by method nand_apply_config.
> > >
> > > This flag controls the bus being used for the NFCs internal RAM access.
> > > It must be set for the DMA use case only.
> > > See A33_Nand_Flash_Controller_Specification.pdf page 12.
> > >
> > > This fix is tested by myself on a Cubietruck A20 board.
> > > Others should test it on new generation SOCs as well.
> >
> > Good to know that someone tackled this, Maxime already reported some
> > time ago that it was broken for a number of boards but I never took the
> > time to investigate, apologies.
>
> Oh, that's awesome, thanks for tackling this :)
>
> Maxime