Messages in this thread | | | Subject | Re: [PATCH] ARM: dts: imx6qdl-nitrogen6_max: Disable LVDS channels | From | Robert Foss <> | Date | Wed, 10 Apr 2019 12:57:23 +0200 |
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Hey Gary,
On 4/10/19 9:35 AM, Gary Bisson wrote: > 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")
I hadn't tried this before, but is seems yo yield the same results
# cat /proc/cmdline video=LVDS-1:d enforcing=0 ip=dhcp rw rootwait root=/dev/mmcblk1p1 log_buf_len=16M cma=512M vmalloc=512M
# dmesg imx-drm display-subsystem: failed to bind disp0 (ops imx_pd_ops): -517 imx-drm display-subsystem: master bind failed: -517
This dmesg log is failing to bind disp0 at another point than what I was seeing before, yet the result is the same. The connected HDMI output is not brought online correctly.
> > 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 > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
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