drm/panel: boe-tv101wum-nl6: restore MODE_LPM after sending disable cmds

commit 570cf79 upstream.

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 error messages shown in kernel log when unblanking on
mt8183-kukui-kodama-sku32 device.

Cc: stable@vger.kernel.org
Fixes: a869b9d ("drm/panel: support for boe tv101wum-nl6 wuxga dsi video mode panel")
Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260503091708.1079962-1-zhengxingda@iscas.ac.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Icenowy

drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c

@@ -1324,6 +1324,8 @@ static int boe_panel_disable(struct drm_panel *panel)
 	mipi_dsi_dcs_set_display_off_multi(&ctx);
 	mipi_dsi_dcs_enter_sleep_mode_multi(&ctx);
 
+	boe->dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
 	mipi_dsi_msleep(&ctx, 150);
 
 	return ctx.accum_err;