LKML Archive mirror
 help / color / mirror / Atom feed
From: Brian Norris <computersforpeace@gmail.com>
To: Bjorn Andersson <quic_bjorande@quicinc.com>
Cc: Johan Hovold <johan@kernel.org>,
	Bjorn Andersson <andersson@kernel.org>,
	 Linus Walleij <linus.walleij@linaro.org>,
	Jaiganesh Narayanan <njaigane@codeaurora.org>,
	 Doug Anderson <dianders@chromium.org>,
	linux-arm-msm@vger.kernel.org,  linux-gpio@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] pinctrl: qcom: Fix behavior in abscense of open-drain support
Date: Fri, 26 Apr 2024 23:18:30 -0700	[thread overview]
Message-ID: <CAN8TOE-o7Sq-ZugRfKEQfkzjozhMS=LZ0Ogj_r3dyUuNO4974A@mail.gmail.com> (raw)
In-Reply-To: <Ziw8OrNS55AtyDkI@hu-bjorande-lv.qualcomm.com>

Hi Bjorn,

On Fri, Apr 26, 2024 at 4:44 PM Bjorn Andersson
<quic_bjorande@quicinc.com> wrote:
> On Fri, Apr 26, 2024 at 03:08:06PM -0700, Brian Norris wrote:
> > Apologies if I broke something here.
>
> False alarm on the breakage part, I got lost in the software layers.

OK! Glad it's not causing a visible problem.

> > But I can't tell based on subsequent conversation: are you observing a
> > real problem, or is this a theoretical one that only exists if the
> > gpiochip driver adds set_config() support?
> >
>
> There is a problem that if a non-ipq4019 device where to be pinconf'ed
> for open-drain, the outcome would be unexpected

Well as observed elsewhere, that's not permitted in most MSM bindings
;) But still might be nice to remove the landmine.

> and I have a concern
> that someone one day would implement set_config().
>
> So, I'd like to fix this, but my argumentation is at least wrong.

Sure.

I haven't surveyed the other pinconf types well, but how does this
driver handle all that? Are all other types supported uniformly by all
qcom pin blocks? It seems a little weird to be treating bit 0 as a
NULL choice, but clearly it works for now, with only a single non-zero
bit user.

> > https://git.kernel.org/linus/99d19f5a48ee6fbc647935de458505e9308078e3
>
> Perhaps we could convert that to yaml?

Ha, sure, perhaps. I don't have time for that soon, but there's a
chance such a patch could materialize in the future.

> Thank you for taking a look, Brian. This was valuable input. I will
> rework this to have a valid motivation - at least.

You're welcome! Glad it's cleared up enough to help move forward.

Regards,
Brian

  reply	other threads:[~2024-04-27  6:18 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-25  3:45 [PATCH] pinctrl: qcom: Fix behavior in abscense of open-drain support Bjorn Andersson
2024-04-25 12:02 ` Johan Hovold
2024-04-25 13:47   ` Bjorn Andersson
2024-04-26 22:08   ` Brian Norris
2024-04-26 23:43     ` Bjorn Andersson
2024-04-27  6:18       ` Brian Norris [this message]
2024-05-03  7:28 ` Linus Walleij
2024-05-03  7:35   ` Johan Hovold

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAN8TOE-o7Sq-ZugRfKEQfkzjozhMS=LZ0Ogj_r3dyUuNO4974A@mail.gmail.com' \
    --to=computersforpeace@gmail.com \
    --cc=andersson@kernel.org \
    --cc=dianders@chromium.org \
    --cc=johan@kernel.org \
    --cc=linus.walleij@linaro.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=linux-gpio@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=njaigane@codeaurora.org \
    --cc=quic_bjorande@quicinc.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).