From b48ccb18e642c96473325bc0e16977dc7cb81f48 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Mon, 25 Mar 2024 14:56:27 -0700 Subject: [PATCH] drm-panel: If drm_panel_dp_aux_backlight() fails, don't fail panel probe If we're using the AUX channel for eDP backlight and it fails to probe for some reason, let's _not_ fail the panel probe. At least one case where we could fail to init the backlight is because of a dead or physically missing panel. As talked about in detail in the earlier patch in this series, ("drm/panel-edp: If we fail to powerup/get EDID, use conservative timings"), this can cause the entire system's display pipeline to fail to come up and that's non-ideal. If we fail to init the backlight for some transitory reason, we should dig in and see if there's a way to fix this (perhaps retries?). Even in that case, though, having a panel whose backlight is stuck at 100% (the default, at least in the panel Samsung ATNA33XC20 I tested) is better than having no panel at all. Reviewed-by: Hsin-Yi Wang Signed-off-by: Douglas Anderson Link: https://patchwork.freedesktop.org/patch/msgid/20240325145626.3.I552e8af0ddb1691cc0fe5d27ea3d8020e36f7006@changeid --- drivers/gpu/drm/panel/panel-edp.c | 8 +++++++- drivers/gpu/drm/panel/panel-samsung-atna33xc20.c | 9 +++++++-- 2 files changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c index 62bc6e1a6cfc..d29bacf25c12 100644 --- a/drivers/gpu/drm/panel/panel-edp.c +++ b/drivers/gpu/drm/panel/panel-edp.c @@ -944,8 +944,14 @@ static int panel_edp_probe(struct device *dev, const struct panel_desc *desc, err = drm_panel_dp_aux_backlight(&panel->base, panel->aux); pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); + + /* + * Warn if we get an error, but don't consider it fatal. Having + * a panel where we can't control the backlight is better than + * no panel. + */ if (err) - goto err_finished_pm_runtime; + dev_warn(dev, "failed to register dp aux backlight: %d\n", err); } drm_panel_add(&panel->base); diff --git a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c index 9c336c71562b..6828a4f24d14 100644 --- a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c +++ b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c @@ -328,9 +328,14 @@ static int atana33xc20_probe(struct dp_aux_ep_device *aux_ep) ret = drm_panel_dp_aux_backlight(&panel->base, aux_ep->aux); pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); + + /* + * Warn if we get an error, but don't consider it fatal. Having + * a panel where we can't control the backlight is better than + * no panel. + */ if (ret) - return dev_err_probe(dev, ret, - "failed to register dp aux backlight\n"); + dev_warn(dev, "failed to register dp aux backlight: %d\n", ret); drm_panel_add(&panel->base); -- 2.20.1