Re: [PATCH 3/3] aspeed/smc: Fix number of dummy cycles for FAST_READ_4 command

[Guenter Roeck]

On 2/3/20 11:45 PM, Cédric Le Goater wrote:
> On 2/3/20 7:09 PM, Guenter Roeck wrote:
> > The Linux kernel recently started using FAST_READ_4 commands.
> > This results in flash read failures. At the same time, the m25p80
> > emulation is seen to read 8 more bytes than expected. Adjusting the
> > expected number of dummy cycles to match FAST_READ fixes the problem.
>
> Which machine are you using for these tests ? the AST2500 evb using
> the w25q256 flash model ?

Correct.

Guenter

> Any how, it looks correct.
>
> Reviewed-by: Cédric Le Goater <address@hidden>
> Fixes: f95c4bffdc4c ("aspeed/smc: snoop SPI transfers to fake dummy cycles")
>
> I think commit ef06ca3946e2 ("xilinx_spips: Add support for RX discard
> and RX drain") needs a similar fix. Adding Francisco.
>
> Thanks,
>
> C.
>
>
> > Signed-off-by: Guenter Roeck <address@hidden>
> > ---
> >   hw/ssi/aspeed_smc.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/hw/ssi/aspeed_smc.c b/hw/ssi/aspeed_smc.c
> > index f0c7bbbad3..61e8fa57d3 100644
> > --- a/hw/ssi/aspeed_smc.c
> > +++ b/hw/ssi/aspeed_smc.c
> > @@ -762,11 +762,11 @@ static int aspeed_smc_num_dummies(uint8_t command)
> >       case FAST_READ:
> >       case DOR:
> >       case QOR:
> > +    case FAST_READ_4:
> >       case DOR_4:
> >       case QOR_4:
> >           return 1;
> >       case DIOR:
> > -    case FAST_READ_4:
> >       case DIOR_4:
> >           return 2;
> >       case QIOR: