From: Gary Bisson <gary.bisson@boundarydevices.com>
To: Robert Foss <robert.foss@collabora.com>
Cc: Fabio Estevam <festevam@gmail.com>,
Shawn Guo <shawnguo@kernel.org>,
Sascha Hauer <s.hauer@pengutronix.de>,
Sascha Hauer <kernel@pengutronix.de>,
Fabio Estevam <fabio.estevam@nxp.com>,
NXP Linux Team <linux-imx@nxp.com>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Troy Kisky <troy.kisky@boundarydevices.com>
Subject: Re: [PATCH] ARM: dts: imx6qdl-nitrogen6_max: Disable LVDS channels
Date: Wed, 10 Apr 2019 09:35:50 +0200 [thread overview]
Message-ID: <CAAMH-ys-S7miJFCAY9bxrDGTPPT7e7c430-_4+edH8scV_qTwA@mail.gmail.com> (raw)
In-Reply-To: <4fd506a1-c961-0569-6d39-283758f363d9@collabora.com>
Hi,
On Tue, Apr 9, 2019 at 2:07 AM Robert Foss <robert.foss@collabora.com> wrote:
>
> Hey Fabio,
>
> On 4/8/19 10:37 PM, Fabio Estevam wrote:
> > Hi Robert,
> >
> > [Adding Gary]
Adding Troy, I'm no longer a full-time employee at Boundary Devices.
> > On Mon, Apr 8, 2019 at 2:54 PM Robert Foss <robert.foss@collabora.com> wrote:
> >>
> >> If a LVDS device is not connected, having the LVDS channels
> >> enabled will prevent imx-ldb from probing correctly even
> >> if other CRTCs are connected.
> >>
> >> Signed-off-by: Robert Foss <robert.foss@collabora.com>
> >> ---
> >> arch/arm/boot/dts/imx6qdl-nitrogen6_max.dtsi | 4 ++--
> >> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/arch/arm/boot/dts/imx6qdl-nitrogen6_max.dtsi b/arch/arm/boot/dts/imx6qdl-nitrogen6_max.dtsi
> >> index 39200e5dc896..5b413cf4c250 100644
> >> --- a/arch/arm/boot/dts/imx6qdl-nitrogen6_max.dtsi
> >> +++ b/arch/arm/boot/dts/imx6qdl-nitrogen6_max.dtsi
> >> @@ -703,7 +703,7 @@
> >> status = "okay";
> >>
> >> lvds-channel@0 {
> >> - status = "okay";
> >> + status = "disabled";
> >>
> >> port@4 {
> >> reg = <4>;
> >> @@ -715,7 +715,7 @@
> >> };
> >>
> >> lvds-channel@1 {
> >> - status = "okay";
> >> + status = "disabled";
> >
> > I am not sure I understood what you are trying to fix.
>
> If CONFIG_DRM_IMX_LDB is enabled, LVDS DT channels are enabled
> and no LVDS-panels are connected the imx-ldb driver will
> fail to bind.
>
> This is a problem, since it will prevent other actually connected
> display output from being used, even if they bind properly.
>
> >
> > Could you please share some logs when imx-ldb fails to probe correctly?
>
>
> [ 2.119563] component_bind_all() trying to bind: ldb
> [ 2.124600] imx-drm display-subsystem: binding ldb (ops imx_ldb_ops)
> [ 2.146169] drm_of_find_panel_or_bridge() np->name=lvds-channel np->type=<NULL>
> [ 2.153709] drm_of_find_panel_or_bridge() no panel found for remote
> [ 2.160081] drm_of_find_panel_or_bridge() bridge needed
> [ 2.162043] drm_of_find_panel_or_bridge() bridge not found
> [ 2.165331] drm_of_find_panel_or_bridge() failed
> [ 2.170023] imx-drm display-subsystem: failed to bind ldb (ops imx_ldb_ops): -517
>
> This at the same time as HDMI binds properly:
>
> [ 4.458954] dwhdmi-imx 120000.hdmi: Detected HDMI TX controller v1.30a with
> HDCP (DWC HDMI 3D TX PHY)
> [ 4.469633] imx-drm display-subsystem: bound 120000.hdmi (ops dw_hdmi_imx_ops)
>
> Which in the end causes the IMX driver to not initialize properly
> and ignore the HDMI connection that bound properly.
> This in turn prevents us from having any graphical output while there
> is no LVDS panel connected.
Does this happen if the LVDS is disabled in cmdline? (adding "video=LVDS-1:d")
Note that a bootscript was written for mainline kernel that takes care
of display configuration [1].
Currently this bootscript disables all the displays that aren't used.
It was tested with HDMI, where LVDS and LCD display are disabled, and
it *used to* work.
If this doesn't work then there's most likely a regression somewhere.
Regards,
Gary
[1] https://github.com/boundarydevices/u-boot-imx6/blob/boundary-v2018.07/board/boundary/bootscripts/bootscript-mainline.txt#L90
next prev parent reply other threads:[~2019-04-10 7:36 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-08 17:53 [PATCH] ARM: dts: imx6qdl-nitrogen6_max: Disable LVDS channels Robert Foss
2019-04-08 20:37 ` Fabio Estevam
2019-04-09 0:07 ` Robert Foss
2019-04-10 7:35 ` Gary Bisson [this message]
2019-04-10 10:57 ` Robert Foss
2019-04-10 11:55 ` Fabio Estevam
2019-04-10 12:00 ` Fabio Estevam
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=CAAMH-ys-S7miJFCAY9bxrDGTPPT7e7c430-_4+edH8scV_qTwA@mail.gmail.com \
--to=gary.bisson@boundarydevices.com \
--cc=devicetree@vger.kernel.org \
--cc=fabio.estevam@nxp.com \
--cc=festevam@gmail.com \
--cc=kernel@pengutronix.de \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-imx@nxp.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=robert.foss@collabora.com \
--cc=robh+dt@kernel.org \
--cc=s.hauer@pengutronix.de \
--cc=shawnguo@kernel.org \
--cc=troy.kisky@boundarydevices.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 NNTP newsgroup(s).