On the working system I get: [ 3.359749] pwm-backlight backlight: Linked as a consumer to regulator.7 [ 8.789867] panel-lvds panel: Linked as a consumer to regulator.8
Non-working: [ 3.362822] pwm-backlight backlight: Linked as a consumer to regulator.7 [ 3.362907] pwm-backlight backlight: Dropping the link to regulator.7 [ 5.441029] pwm-backlight backlight: Linked as a consumer to regulator.7 [ 5.447941] pwm-backlight backlight: Dropping the link to regulator.7 ... [ 8.810651] panel-lvds panel: Linked as a consumer to regulator.8 [ 8.816878] panel-lvds panel: Dropping the link to regulator.8 [ 8.976370] panel-lvds panel: Linked as a consumer to regulator.8 [ 9.063164] panel-lvds panel: Dropping the link to regulator.8 [ 9.208480] panel-lvds panel: Linked as a consumer to regulator.8 [ 9.214729] panel-lvds panel: Dropping the link to regulator.8
You are right, I didn't notice that before! Thank you for having a look!
Regards, Stefan
On Tue, 2020-08-11 at 14:50 +0000, Stefan Birkholz wrote:
Hello,
we are using the mainline kernel (currently on 4.19.128) successfully on an i.MX6DL-based system, but when we try to upgrade to any more recent kernel (>5.1) the display output stops working (screen is blank, backlight works).
The relevant entries from the kernel log seem to be: [ 8.954942] imx-drm display-subsystem: bound imx-ipuv3-crtc.3 (ops imx_drm_exit [imxdrm]) [ 9.028406] imx-drm display-subsystem: failed to bind disp0 (ops imx_pd_ops [parallel_display]): -517 [ 9.037873] imx-drm display-subsystem: master bind failed: -517
The only call in imx_pd_bind() I would expect to return -EPROBE_DEFER is drm_of_find_panel_or_bridge(), maybe parallel-display node's port@1 is connected to a panel that is not registered. Are the drivers for the panel and all its dependencies (power supply regulator, backlight) enabled and probed?
regards Philipp