[PATCH] drm/panel: himax-hx83102: restore MODE_LPM after sending disable cmds

[Icenowy Zheng <zhengxingda@iscas.ac.cn>]

When preparing the panel, it seems that it always expects commands to be
transferred in LP mode. However, the disable function removes the
MIPI_DSI_MODE_LPM flag, and no other function re-adds it.

As the unprepare function contains no DSI commands, re-adding the flag
just after disabling the panel should be safe. Add the code re-adding
the flag after the two commands for disabling the panel are sent.

This fixes screen unblanking (after blanking once) on
mt8188-geralt-ciri-sku1 device.

Cc: stable@vger.kernel.org # 6.11+
Fixes: 0ef94554dc40 ("drm/panel: himax-hx83102: Break out as separate driver")
Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
---
 drivers/gpu/drm/panel/panel-himax-hx83102.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/panel/panel-himax-hx83102.c b/drivers/gpu/drm/panel/panel-himax-hx83102.c
index 8b2a68ee851e3..a5e5c9ea7a73f 100644
--- a/drivers/gpu/drm/panel/panel-himax-hx83102.c
+++ b/drivers/gpu/drm/panel/panel-himax-hx83102.c
@@ -937,6 +937,8 @@ static int hx83102_disable(struct drm_panel *panel)
 	mipi_dsi_dcs_set_display_off_multi(&dsi_ctx);
 	mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx);
 
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
 	mipi_dsi_msleep(&dsi_ctx, 150);
 
 	return dsi_ctx.accum_err;
-- 
2.52.0