drm/i915/dsi: Init panel-enable GPIO to low when the LCD is initially off (v2)

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.

Changes in v2:
- Call intel_dsi_get_hw_state() to check if the panel is on instead of
  relying on the current_mode pointer

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191216205122.1850923-4-hdegoede@redhat.com

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_dsi.h b/drivers/gpu/drm/i915/display/intel_dsi.h
index de7e51cd3460..675771ea91aa 100644
--- a/drivers/gpu/drm/i915/display/intel_dsi.h
+++ b/drivers/gpu/drm/i915/display/intel_dsi.h
@@ -203,7 +203,7 @@ void bxt_dsi_reset_clocks(struct intel_encoder *encoder, enum port port);
 
 /* intel_dsi_vbt.c */
 bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi, u16 panel_id);
-void intel_dsi_vbt_gpio_init(struct intel_dsi *intel_dsi);
+void intel_dsi_vbt_gpio_init(struct intel_dsi *intel_dsi, bool panel_is_on);
 void intel_dsi_vbt_gpio_cleanup(struct intel_dsi *intel_dsi);
 void intel_dsi_vbt_exec_sequence(struct intel_dsi *intel_dsi,
 				 enum mipi_seq seq_id);