Re: [PATCH v4 1/3] spi: add SPI_MOSI_IDLE_LOW mode bit

From: Börge Strümpfel
Date: Wed May 17 2023 - 20:27:52 EST


Am Do., 18. Mai 2023 um 01:53 Uhr schrieb Fabio Estevam <festevam@xxxxxxxxx>:
>
> On Wed, May 17, 2023 at 8:20 PM Börge Strümpfel
> <boerge.struempfel@xxxxxxxxx> wrote:
>
> > My bad. Thanks for letting me know. Just to clarify: I put the
> > changelog directly below
> > the first ---? And do I then put another --- between the changelog and
> > the following
> > include/uapi/linux/spi/spi.h | 3 ++- line? or is there just a
> > new-line seperating them.
>
> It should look like this:
>
> Commit log line 1
> Commit log line 2
> ...
> Commit log line n
>
> Signed-off-by: Your name <your@xxxxxxxxx>
> ---
> Changes since v3:
> - Bla bla bla
>

Thank you for taking the time to explain this!

> > And if you don't mind my trivial questions, am I supposed to write a
> > cover letter for
> > the patch-stack? I seem to find contradictory answers to this question online.
>
> Yes, for a patch series having a cover letter is helpful.
>

I will add one for the next version.

> > > Should tools/spi/spidev_test.c be changed to include this new
> > > mosi-idle-low option?
> >
> > Until now I actually wasn't aware of this tool. However on first
> > glance, it seems
> > reasonable to add this mode bit. I can certainly add this mode bit to
> > the spidev_test
> > if desired.
>
> Yes, that would be great.
>

Okay. I have begun to implement this. During this, I noticed, that if
I called the new option
"--mosi-idle-low", the alignment of the help-lines (and in the c code
itself) would break.
Should I therefore shorten the option name by using an abbreviation
like "--mil", which is
probably not very helpful as a "full option name", or should I touch
all the other lines and
insert necessary spaces, such that they are aligned once more? (And if
so, should I do
this in a seperate patch, preparing the addition of the new options?)

> > While looking through the code, I noticed, that the latest two
> > additions to the spi->mode
> > (SPI_3WIRE_HIZ and SPI_RX_CPHA_FLIP) are also missing from this tool. Is this
> > by design, or should they then be included as well?
>
> Looks like these two are missing and would be good to get them included as well.

Okay. Should this be a separate patch, or should I add the support for
all 3 mode bits in
one commit?