Re: [PATCH v2 0/3] spi: sh-msiof: Add reset of registers before starting transfer

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

Hi Wolfram,

On Tue, Apr 2, 2019 at 4:47 PM Wolfram Sang <wsa@xxxxxxxxxxxxx> wrote:
> >   - New patches 1 and 2, in response to review comments on v1
> >     (although sh_msiof_modify_ctr_wait() didn't turn out to be suitable
> >     for calling by sh_msiof_spi_reset_regs()),
>
> Well, the overhead of readl_poll_timeout_atomic() is low enough to
> ignore reusing sh_msiof_modify_ctr_wait IMO. Thanks for doing it!

sh_msiof_modify_ctr_wait() cannot be used because it checks when the
change just made to the register becomes visible (i.e. new state can
be read back).
For reset the check is different: the write sets the bit, the check
must wait until
the hardware has cleared the bit again.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds