[U-Boot] [PATCH v3 08/16] tegra: nand: fix read_byte required for proper onfi detection

[Scott Wood]

On Thu, 2015-08-06 at 00:47 +0200, Marcel Ziswiler wrote:
> From: Marcel Ziswiler <marcel.ziswiler at toradex.com>
> 
> Fix PIO read_byte() implementation not only used for the legacy READ ID
> but also the PARAM command required for proper ONFI detection.
> 
> This fix is inspired by Lucas Stach's Linux Tegra NAND driver of late
> (not mainline yet but getting there soon I hope).
> 
> I vaguely remember that those commands are special on 16-bit bus NAND
> (e.g. always return 8-bit data regardless) and later Linux MTD fixed/
> changed the way this is handled which in turn broke once U-Boot pulled
> that in. Basically instead of doing PIO read regular DMA block read is
> now used which this patch actually fixes.
> 
> Signed-off-by: Marcel Ziswiler <marcel.ziswiler at toradex.com>
> ---
> Chances in v3:
> - add more detailed commit message as suggested by Scott
> - drop unrelated subpage writes disabling to be done as part of a
>   separate patch as suggested by Scott
> 
>  drivers/mtd/nand/tegra_nand.c | 38 +++++++-------------------------------
>  1 file changed, 7 insertions(+), 31 deletions(-)

Acked-by: Scott Wood <scottwood at freescale.com>

-Scott