[PATCH] drm/panel: boe-tv101wum-nl6: make use of prepare_prev_first

[Douglas Anderson <dianders@chromium.org>]

The panel on sc7180-trogdor-wormdingler and
sc7180-trogdor-quackingstick hasn't been coming up since commit
9e15123eca79 ("drm/msm/dsi: Stop unconditionally powering up DSI hosts
at modeset"). Let's add "prepare_prev_first" as has been done for many
other DSI panels.

Fixes: 9e15123eca79 ("drm/msm/dsi: Stop unconditionally powering up DSI hosts at modeset")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
This of course gets into debates about getting a nicer solution that
doesn't involve adding "prepare_prev_first" to every DSI panel out
there, maybe building on Dmitry's work [1]. While it would be nice if
we could get there, getting this landed is easy to backport to stable
trees and gets the panel working again.

[1] https://lore.kernel.org/r/20231016165355.1327217-4-dmitry.baryshkov@linaro.org

 drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c b/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
index c4c0f08e9202..bc08814954f9 100644
--- a/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
+++ b/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
@@ -1871,6 +1871,8 @@ static int boe_panel_add(struct boe_panel *boe)
 
 	gpiod_set_value(boe->enable_gpio, 0);
 
+	boe->base.prepare_prev_first = true;
+
 	drm_panel_init(&boe->base, dev, &boe_panel_funcs,
 		       DRM_MODE_CONNECTOR_DSI);
 	err = of_drm_get_panel_orientation(dev->of_node, &boe->orientation);
-- 
2.44.0.rc0.258.g7320e95886-goog