drm/bridge: cdns-dsi: Fix phy de-init and flag it so

commit fd2611c upstream.

The driver code doesn't have a Phy de-initialization path as yet, and so
it does not clear the phy_initialized flag while suspending. This is a
problem because after resume the driver looks at this flag to determine
if a Phy re-initialization is required or not. It is in fact required
because the hardware is resuming from a suspend, but the driver does not
carry out any re-initialization causing the D-Phy to not work at all.

Call the counterparts of phy_init() and phy_power_on(), that are
phy_exit() and phy_power_off(), from _bridge_post_disable(), and clear
the flags so that the Phy can be initialized again when required.

Fixes: fced5a3 ("drm/bridge: cdns: Convert to phy framework")
Cc: [email protected]
Reviewed-by: Dmitry Baryshkov <[email protected]>
Reviewed-by: Tomi Valkeinen <[email protected]>
Tested-by: Tomi Valkeinen <[email protected]>
Signed-off-by: Aradhya Bhatia <[email protected]>
Signed-off-by: Aradhya Bhatia <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Dmitry Baryshkov <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Aradhya Bhatia

drivers/gpu/drm/bridge/cdns-dsi.c

@@ -718,6 +718,11 @@ static void cdns_dsi_bridge_post_disable(struct drm_bridge *bridge)
 	struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
 	struct cdns_dsi *dsi = input_to_dsi(input);
 
+	dsi->phy_initialized = false;
+	dsi->link_initialized = false;
+	phy_power_off(dsi->dphy);
+	phy_exit(dsi->dphy);
+
 	pm_runtime_put(dsi->base.dev);
 }
 
@@ -1187,7 +1192,6 @@ static int __maybe_unused cdns_dsi_suspend(struct device *dev)
 	clk_disable_unprepare(dsi->dsi_sys_clk);
 	clk_disable_unprepare(dsi->dsi_p_clk);
 	reset_control_assert(dsi->dsi_p_rst);
-	dsi->link_initialized = false;
 	return 0;
 }