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

[Francisco Iglesias]

Hi Cédric,

On [2020 Feb 04] Tue 08:45:11, 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 ? 
> 
> 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.

Yes, I agree that a similar fix is needed in the xilinx_spips aswell, I just
provided a patch. Thank you for the notification!

Best regards,
Francisco Iglesias

> 
> 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:
> > 
>