[U-Boot] [PATCH v3 13/20] spl: nand: sunxi: use PIO instead of DMA

[Miquel Raynal]

Hi Maxime,

Maxime Ripard <maxime at cerno.tech> wrote on Thu, 24 Jun 2021 14:05:40
+0200:

> Hi Miquel,
> 
> On Wed, Feb 28, 2018 at 08:51:55PM +0100, Miquel Raynal wrote:
> > SPL support was first written to support only the earlier generations of
> > Allwinner SoCs, and was only really enabled on the A13 / GR8. However,
> > those old SoCs had a DMA engine that has been replaced since the A31 by
> > another DMA controller that is no longer compatible.
> > 
> > Since the code directly uses that DMA controller, it cannot operate
> > properly on the later SoCs, while the NAND controller has not changed.
> > 
> > There's two paths forward, the first one would have been to add support
> > for that DMA controller too, the second to just remove the DMA usage
> > entirely and rely on PIO.
> > 
> > The later has been chosen because CPU overload at this stage is not an
> > issue and it makes the driver more generic, and easier to understand.
> > 
> > Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>
> > Acked-by: Boris Brezillon <boris.brezillon at bootlin.com>  
> 
> I'm a bit late to the party, but this bricks the CHIP Pro too. While
> U-Boot proper seems to be flashed properly (re-reading it from the NAND
> after flashing brings up the same CRC than the original image), the SPL
> will only read 0s.
> 
> The transfer does complete though, so maybe it's just the copy from the
> SRAM to the main memory that doesn't work?
> 
> The offset looks correct though, so I'm not sure.

Strange... I really have no idea what's going on here and especially I
don't have any suitable board with me these days to troubleshoot this.

Sorry for not being helpful at all on this one :-)

Thanks,
Miquèl