drm/panel: st7701: Add prepare_prev_first flag to drm_panel

[ Upstream commit 406dd4c7984a457567ca652455d5efad81983f02 ]

The DSI host must be enabled for the panel to be initialized in
prepare(). Set the prepare_prev_first flag to guarantee this.
This fixes the panel operation on NXP i.MX8MP SoC / Samsung DSIM
DSI host.

Fixes: 849b2e3ff969 ("drm/panel: Add Sitronix ST7701 panel driver")
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Link: https://lore.kernel.org/r/20241124224812.150263-1-marex@denx.de
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241124224812.150263-1-marex@denx.de
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7701.c b/drivers/gpu/drm/panel/panel-sitronix-st7701.c
index eef03d04e0cd2de6d95e26aed4478a4f029eecb5..1f72ef7ca74c9382aa103cc7c65fdedc7e4755b3 100644 (file)
--- a/drivers/gpu/drm/panel/panel-sitronix-st7701.c
+++ b/drivers/gpu/drm/panel/panel-sitronix-st7701.c
@@ -1177,6 +1177,7 @@ static int st7701_probe(struct device *dev, int connector_type)
                return dev_err_probe(dev, ret, "Failed to get orientation\n");
 
        drm_panel_init(&st7701->panel, dev, &st7701_funcs, connector_type);
+       st7701->panel.prepare_prev_first = true;
 
        /**
         * Once sleep out has been issued, ST7701 IC required to wait 120ms