All of lore.kernel.org
 help / color / mirror / Atom feed
From: Thierry Reding <thierry.reding@gmail.com>
To: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Sam Ravnborg <sam@ravnborg.org>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] drm/panel: Make backlight attachment lazy
Date: Tue, 8 Dec 2020 13:47:56 +0100	[thread overview]
Message-ID: <X891/LvEJT1bLtjH@ulmo> (raw)
In-Reply-To: <20201208044446.973238-1-bjorn.andersson@linaro.org>

[-- Attachment #1: Type: text/plain, Size: 925 bytes --]

On Mon, Dec 07, 2020 at 10:44:46PM -0600, Bjorn Andersson wrote:
> Some bridge chips, such as the TI SN65DSI86 DSI/eDP bridge, provides
> means of generating a PWM signal for backlight control of the attached
> panel. The provided PWM chip is typically controlled by the
> pwm-backlight driver, which if tied to the panel will provide DPMS.
> 
> But with the current implementation the panel will refuse to probe
> because the bridge driver has yet to probe and register the PWM chip,
> and the bridge driver will refuse to probe because it's unable to find
> the panel.

What you're describing is basically a circular dependency. Can't we get
rid of that in some other way? Why exactly does the bridge driver refuse
to probe if the panel can't be found?

In other words, I see how the bridge would /use/ the panel in that it
forward a video stream to it. But how does the panel /use/ the bridge?

Thierry

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

WARNING: multiple messages have this Message-ID (diff)
From: Thierry Reding <thierry.reding@gmail.com>
To: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>,
	David Airlie <airlied@linux.ie>,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	Sam Ravnborg <sam@ravnborg.org>
Subject: Re: [RFC PATCH] drm/panel: Make backlight attachment lazy
Date: Tue, 8 Dec 2020 13:47:56 +0100	[thread overview]
Message-ID: <X891/LvEJT1bLtjH@ulmo> (raw)
In-Reply-To: <20201208044446.973238-1-bjorn.andersson@linaro.org>


[-- Attachment #1.1: Type: text/plain, Size: 925 bytes --]

On Mon, Dec 07, 2020 at 10:44:46PM -0600, Bjorn Andersson wrote:
> Some bridge chips, such as the TI SN65DSI86 DSI/eDP bridge, provides
> means of generating a PWM signal for backlight control of the attached
> panel. The provided PWM chip is typically controlled by the
> pwm-backlight driver, which if tied to the panel will provide DPMS.
> 
> But with the current implementation the panel will refuse to probe
> because the bridge driver has yet to probe and register the PWM chip,
> and the bridge driver will refuse to probe because it's unable to find
> the panel.

What you're describing is basically a circular dependency. Can't we get
rid of that in some other way? Why exactly does the bridge driver refuse
to probe if the panel can't be found?

In other words, I see how the bridge would /use/ the panel in that it
forward a video stream to it. But how does the panel /use/ the bridge?

Thierry

[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

[-- Attachment #2: Type: text/plain, Size: 160 bytes --]

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

  parent reply	other threads:[~2020-12-08 12:48 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-08  4:44 [RFC PATCH] drm/panel: Make backlight attachment lazy Bjorn Andersson
2020-12-08  4:44 ` Bjorn Andersson
2020-12-08  5:48 ` Sam Ravnborg
2020-12-08  5:48   ` Sam Ravnborg
2020-12-08 21:39   ` Bjorn Andersson
2020-12-08 21:39     ` Bjorn Andersson
2020-12-08 12:47 ` Thierry Reding [this message]
2020-12-08 12:47   ` Thierry Reding
2020-12-08 22:02   ` Bjorn Andersson
2020-12-08 22:02     ` Bjorn Andersson
2020-12-08 23:52     ` Daniel Vetter
2020-12-08 23:52       ` Daniel Vetter
2020-12-09 20:28       ` Bjorn Andersson
2020-12-09 20:28         ` Bjorn Andersson
2020-12-10 10:15         ` Daniel Vetter
2020-12-10 10:15           ` Daniel Vetter
2020-12-10 16:44           ` Thierry Reding
2020-12-10 16:44             ` Thierry Reding
2020-12-10 16:50             ` Daniel Vetter
2020-12-10 16:50               ` Daniel Vetter
2020-12-10 17:18               ` Thierry Reding
2020-12-10 17:18                 ` Thierry Reding

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=X891/LvEJT1bLtjH@ulmo \
    --to=thierry.reding@gmail.com \
    --cc=airlied@linux.ie \
    --cc=bjorn.andersson@linaro.org \
    --cc=daniel@ffwll.ch \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=maarten.lankhorst@linux.intel.com \
    --cc=mripard@kernel.org \
    --cc=sam@ravnborg.org \
    --cc=tzimmermann@suse.de \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.