On Thu, Jun 11, 2026 at 1:43 PM Icenowy Zheng <[email protected]> wrote: > > 在 2026-06-11四的 13:26 +0800，Pengyu Luo写道： > > On Tue, 09 Jun 2026 00:26:22 +0800, Icenowy Zheng > > <[email protected]> wrote: > > > diff --git a/drivers/gpu/drm/panel/panel-himax-hx83121a.c > > > b/drivers/gpu/drm/panel/panel-himax-hx83121a.c > > > index 1a7e0125bced..e31e2fba0a78 100644 > > > --- a/drivers/gpu/drm/panel/panel-himax-hx83121a.c > > > +++ b/drivers/gpu/drm/panel/panel-himax-hx83121a.c > > > @@ -195,7 +197,27 @@ static int himax_bl_update_status(struct > > > backlight_device *bl) > > > [ ... skip 18 lines ... ] > > > + ret = regulator_enable(ctx->bl_supply); > > > + if (ret) > > > + return ret; > > > + > > > + ctx->backlight_enabled = true; > > > + > > > > If you use a pin, (it is indeed a hwen pin as we know) you can > > simplify it like this, > > > > bool bl_enable_now = !!brightness; > > > > if (ctx->bl_enable != bl_enable_now) { > > gpiod_set_value(ctx->hwen_gpio, bl_enable_now); > > ctx->bl_enable = bl_enable_now; > > } > > > > BTW, iirc, panel bias can be turned off too, although I don't think > > this will save too much power. > > BTW during my test, it seems that DCS backlight 0 isn't turning off > backlight. >
Yes, there is a hwen pin to turn off BL. In the downstream, I added it, no time to upstream it, I forgot to add display DT too. I meant you can turn off panel bias too, if you turn off BL. In general, I turn off it in drm_panel_unprepare() Best wishes, Pengyu
