[PATCH 01/11] spi: rk: Limit transfers to (64K - 1) bytes

[Jagan Teki]

On Mon, Dec 23, 2019 at 8:00 AM Kever Yang <kever.yang at rock-chips.com> wrote:
>
>
> On 2019/12/21 下午3:54, Jagan Teki wrote:
> > The Rockchip SPI controller's length register only supports 16-bits,
> > yielding a maximum length of 64KiB (the CTRLR1 register holds "length -
> > 1"). Trying to transfer more than that (e.g., with a large SPI flash
> > read) will cause the driver to hang.
> >
> > Now, it seems that while theoretically we should be able to program
> > CTRLR1 with 0xffff, and get a 64KiB transfer, but that also seems to
> > cause the core to choke, so stick with a maximum of 64K - 1 bytes --
> > i.e., 0xffff.
> >
> > Note, that the size is further divided into 'minus 1' while writing
> > into CTRLR1.
> >
> > This change fixed two different read issues,
> >
> > 1. sf read failure when with > 0x10000
> >
> > 2. Boot from SPI flash failed during spi_flash_read call in
> >     common/spl/spl_spi.c
> >
> > Observed and Tested in
> > - Rockpro64 with Gigadevice flash
> > - ROC-RK3399-PC with Winbond flash
> >
> > Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
>
> Reviewed-by: Kever Yang <kever.yang at rock-chips.com>

Applied to u-boot-spi/master