[Intel-gfx] [PATCH 3/5] drm/i915/dsi: Init panel-enable GPIO to low when the LCD is initially off

[Linus Walleij]

On Sun, Dec 15, 2019 at 5:38 PM Hans de Goede <hdegoede at redhat.com> wrote:

> When the LCD has not been turned on by the firmware/GOP, because e.g. the
> device was booted with an external monitor connected over HDMI, we should
> not turn on the panel-enable GPIO when we request it.
>
> Turning on the panel-enable GPIO when we request it, means we turn it on
> too early in the init-sequence, which causes some panels to not correctly
> light up.
>
> This commits adds a panel_is_on parameter to intel_dsi_vbt_gpio_init()
> and makes intel_dsi_vbt_gpio_init() set the initial GPIO value accordingly.
>
> This fixes the panel not lighting up on a Thundersoft TST168 tablet when
> booted with an external monitor connected over HDMI.
>
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>

Reviewed-by: Linus Walleij <linus.walleij at linaro.org>

Yours,
Linus Walleij