public inbox for linux-arm-kernel@lists.infradead.org
 help / color / mirror / Atom feed
From: viresh.kumar@linaro.org (Viresh Kumar)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC v2 5/6] drivers: boot_constraint: Add initial DT bindings
Date: Thu, 13 Jul 2017 10:39:34 +0530	[thread overview]
Message-ID: <20170713050934.GB352@vireshk-i7> (raw)
In-Reply-To: <CAGb2v67XtUcqdjMt-Ln6zn3ShH4JFmjkK4bPSpUNZpJqnmwivw@mail.gmail.com>

On 13-07-17, 10:52, Chen-Yu Tsai wrote:
> I'm afraid the regulator case still doesn't make sense. The voltage
> constraints should be set within each supplies device node. This was
> explained in the discussion in v1 [1].

I thought we were discussing about something I mentioned in one of my example
but never to a point that the regulator problem doesn't exist at all. Perhaps I
misunderstood your concerns. Anyway, lemme try once more with a better example.

Regulator shared by: LCD and MMC (both can do DVFS) and the min/max constraint
that can be set by the consumers of the regulator (both LCD/MMC) are: 1.5 V to
3 V.

The bootloader has programmed the LCD to work at the highest pixel frequency,
which needs the voltage to be in range from 2.5 - 3 V.

Now MMC can get probed first and it can try to bring the voltages below 2.5 V.
Though, 1.5 - 2.5 is a valid range for the LCD, but not at the current pixel
frequency.

Does that sound like a valid problem?

-- 
viresh

  reply	other threads:[~2017-07-13  5:09 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-12  6:34 [RFC v2 0/6] drivers: Boot Constraints core Viresh Kumar
2017-07-12  6:34 ` [RFC v2 1/6] drivers: Add boot constraints core Viresh Kumar
2017-07-12  6:34 ` [RFC v2 2/6] drivers: boot_constraint: Add support for supply constraints Viresh Kumar
2017-07-12  6:34 ` [RFC v2 3/6] drivers: boot_constraint: Add boot_constraints_disable kernel parameter Viresh Kumar
2017-07-12  6:34 ` [RFC v2 4/6] drivers: boot_constraint: Add debugfs support Viresh Kumar
2017-07-12  7:18   ` Viresh Kumar
2017-07-12  6:34 ` [RFC v2 5/6] drivers: boot_constraint: Add initial DT bindings Viresh Kumar
2017-07-12 21:28   ` Rob Herring
2017-07-13  2:52     ` Chen-Yu Tsai
2017-07-13  5:09       ` Viresh Kumar [this message]
2017-07-13  9:46         ` Chen-Yu Tsai
2017-07-13  9:51           ` Viresh Kumar
2017-07-13  9:36     ` Viresh Kumar
2017-07-17 17:34       ` Rob Herring
2017-07-18  5:58         ` Viresh Kumar
2017-07-12  6:34 ` [RFC v2 6/6] drivers: boot_constraint: Add constraints for OF devices Viresh Kumar

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=20170713050934.GB352@vireshk-i7 \
    --to=viresh.kumar@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    /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