[PATCH 1/2] Revert "rockchip: spi: fix off-by-one in chunk size computation"

[Jagan Teki]

On Wed, 11 Dec, 2019, 7:10 PM Philipp Tomsich, <
philipp.tomsich at theobroma-systems.com> wrote:

>
>
> > On 11.12.2019, at 14:26, Jagan Teki <jagan at amarulasolutions.com> wrote:
> >
> > The maximum transfer length (in a single transaction) for the Rockchip
> > SPI controller is 64Kframes (i.e. 0x10000 frames) of 8bit or 16bit
> > frames and is encoded as (num_frames - 1) in CTRLR1.
> >
> > So the 0x10000 is offset value for 64K but the actual size value would
> > be 'minus 1' from 0x10000.
>
> NAK. Please see 2 code lines below your change to see that the “minus 1”
> is applied there… so a todo of 0x10000 will write 0xffff to regs->ctrlr1.
>
> The problem must be somewhere else and this patch will only mask the
> underlying issue.
>
> >
> > With the existing code of 0x10000 transfer length leads to read
> > failure when we try to read the flash with > 0x10000 size like,
> >
> > 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
> >
> > This reverts commit e647decdd93c7408741329432f26758fbec04c7a.
> >
> > Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
> > ---
> > drivers/spi/rk_spi.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/spi/rk_spi.c b/drivers/spi/rk_spi.c
> > index c04535ac44..d9a310ce80 100644
> > --- a/drivers/spi/rk_spi.c
> > +++ b/drivers/spi/rk_spi.c
> > @@ -451,7 +451,7 @@ static int rockchip_spi_xfer(struct udevice *dev,
> unsigned int bitlen,
> >
> >       /* This is the original 8bit reader/writer code */
> >       while (len > 0) {
> > -             int todo = min(len, 0x10000);
> > +             int todo = min(len, 0xffff);
> >
> >               rkspi_enable_chip(regs, false);
> >               writel(todo - 1, &regs->ctrlr1);
> > --
> > 2.18.0.321.gffc6fa0e3
> >
>

I have looked multiple areas but didn't get it so and i belive offset and
size values aren't same.

 Would you please send me the log of sf read to more than 64K on your
hardware? This would confirm my hardware issue if you succeed.

>