linux-kernel - Re: [PATCH v3 5/5] spi: spi-geni-qcom: Don't keep a local state variable

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Date:   Thu, 18 Jun 2020 08:05:52 -0700
From:   Doug Anderson <dianders@...omium.org>
To:     Stephen Boyd <swboyd@...omium.org>
Cc:     Mark Brown <broonie@...nel.org>,
        Alok Chauhan <alokc@...eaurora.org>, skakit@...eaurora.org,
        Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        linux-arm-msm <linux-arm-msm@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        linux-spi <linux-spi@...r.kernel.org>
Subject: Re: [PATCH v3 5/5] spi: spi-geni-qcom: Don't keep a local state variable

Hi,

On Wed, Jun 17, 2020 at 2:16 PM Stephen Boyd <swboyd@...omium.org> wrote:
>
> Quoting Douglas Anderson (2020-06-16 03:40:50)
> > diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
> > index 63a62548b078..6feea88d63ac 100644
> > --- a/drivers/spi/spi-geni-qcom.c
> > +++ b/drivers/spi/spi-geni-qcom.c
> > @@ -63,13 +63,6 @@
> >  #define TIMESTAMP_AFTER                BIT(3)
> >  #define POST_CMD_DELAY         BIT(4)
> >
> > -enum spi_m_cmd_opcode {
> > -       CMD_NONE,
> > -       CMD_XFER,
> > -       CMD_CS,
> > -       CMD_CANCEL,
> > -};
> > -
> >  struct spi_geni_master {
> >         struct geni_se se;
> >         struct device *dev;
> > @@ -81,10 +74,11 @@ struct spi_geni_master {
> >         unsigned int tx_rem_bytes;
> >         unsigned int rx_rem_bytes;
> >         const struct spi_transfer *cur_xfer;
> > -       struct completion xfer_done;
> > +       struct completion cs_done;
> > +       struct completion cancel_done;
> > +       struct completion abort_done;
>
> I wonder if it would be better to use the wait_bit() APIs. That would
> let us have one word for various bits like CS_DONE, CANCEL_DONE,
> ABORT_DONE and then wake up the waiters when the particular bit happens
> to come in through the isr. It is probably over-engineering though
> because it saves a handful of bytes while increasing complexity.
>
> Otherwise I like this patch.

I'm going to leave it as-is for v4.  We can always make it a future
improvement if we want.

-Doug