[PATCH v2 2/2] drm/bridge: dw-hdmi: Always add the bridge in the global bridge list

[Liu Ying]

It doesn't hurt to add the bridge in the global bridge list also for
platform specific dw-hdmi drivers which are based on the component
framework.  This can be achieved by moving the drm_bridge_add() function
call from dw_hdmi_probe() to __dw_hdmi_probe().  A counterpart movement
for drm_bridge_remove() is also needed then.  Moreover, since drm_bridge_add()
initializes &bridge->hpd_mutex, this may help those platform specific
dw-hdmi drivers(based on the component framework) avoid accessing the
uninitialized mutex in drm_bridge_hpd_notify() which is called in
dw_hdmi_irq().  Putting drm_bridge_add() in __dw_hdmi_probe() just before
it returns successfully should bring no logic change for platforms based
on the DRM bridge API, which is a good choice from safety point of view.
Also, __dw_hdmi_probe() is renamed to dw_hdmi_probe() since dw_hdmi_probe()
does nothing else but calling __dw_hdmi_probe().  Similar renaming applies
to the __dw_hdmi_remove()/dw_hdmi_remove() pair.

Fixes: ec971aaa6775 ("drm: bridge: dw-hdmi: Make connector creation optional")
Cc: Andrzej Hajda <a.hajda at samsung.com>
Cc: Neil Armstrong <narmstrong at baylibre.com>
Cc: Laurent Pinchart <Laurent.pinchart at ideasonboard.com>
Cc: Jonas Karlman <jonas at kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec at siol.net>
Cc: David Airlie <airlied at linux.ie>
Cc: Daniel Vetter <daniel at ffwll.ch>
Cc: Boris Brezillon <boris.brezillon at collabora.com>
Cc: Jerome Brunet <jbrunet at baylibre.com>
Cc: Cheng-Yi Chiang <cychiang at chromium.org>
Cc: Dariusz Marcinkiewicz <darekm at google.com>
Cc: Archit Taneja <architt at codeaurora.org>
Cc: Jose Abreu <joabreu at synopsys.com>
Cc: Sam Ravnborg <sam at ravnborg.org>
Cc: dri-devel at lists.freedesktop.org
Cc: NXP Linux Team <linux-imx at nxp.com>
Signed-off-by: Liu Ying <victor.liu at nxp.com>
---
v1->v2:
* Put drm_bridge_add() in __dw_hdmi_probe() just before it returns
  successfully so that the bridge shows up in the global bridge list
  late enough to avoid potential race condition with other display
  drivers. (Laurent)
* Rename __dw_hdmi_probe/remove() to dw_hdmi_probe/remove()
  respectively. (Laurent)
* Cc'ed Sam.

 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 44 +++++++++----------------------
 1 file changed, 13 insertions(+), 31 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 137b6eb..748df1c 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -3179,9 +3179,11 @@ static void dw_hdmi_init_hw(struct dw_hdmi *hdmi)
 		hdmi->phy.ops->setup_hpd(hdmi, hdmi->phy.data);
 }
 
-static struct dw_hdmi *
-__dw_hdmi_probe(struct platform_device *pdev,
-		const struct dw_hdmi_plat_data *plat_data)
+/* -----------------------------------------------------------------------------
+ * Probe/remove API, used from platforms based on the DRM bridge API.
+ */
+struct dw_hdmi *dw_hdmi_probe(struct platform_device *pdev,
+			      const struct dw_hdmi_plat_data *plat_data)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
@@ -3438,6 +3440,8 @@ __dw_hdmi_probe(struct platform_device *pdev,
 		hdmi->cec = platform_device_register_full(&pdevinfo);
 	}
 
+	drm_bridge_add(&hdmi->bridge);
+
 	return hdmi;
 
 err_iahb:
@@ -3451,9 +3455,12 @@ __dw_hdmi_probe(struct platform_device *pdev,
 
 	return ERR_PTR(ret);
 }
+EXPORT_SYMBOL_GPL(dw_hdmi_probe);
 
-static void __dw_hdmi_remove(struct dw_hdmi *hdmi)
+void dw_hdmi_remove(struct dw_hdmi *hdmi)
 {
+	drm_bridge_remove(&hdmi->bridge);
+
 	if (hdmi->audio && !IS_ERR(hdmi->audio))
 		platform_device_unregister(hdmi->audio);
 	if (!IS_ERR(hdmi->cec))
@@ -3472,31 +3479,6 @@ static void __dw_hdmi_remove(struct dw_hdmi *hdmi)
 	else
 		i2c_put_adapter(hdmi->ddc);
 }
-
-/* -----------------------------------------------------------------------------
- * Probe/remove API, used from platforms based on the DRM bridge API.
- */
-struct dw_hdmi *dw_hdmi_probe(struct platform_device *pdev,
-			      const struct dw_hdmi_plat_data *plat_data)
-{
-	struct dw_hdmi *hdmi;
-
-	hdmi = __dw_hdmi_probe(pdev, plat_data);
-	if (IS_ERR(hdmi))
-		return hdmi;
-
-	drm_bridge_add(&hdmi->bridge);
-
-	return hdmi;
-}
-EXPORT_SYMBOL_GPL(dw_hdmi_probe);
-
-void dw_hdmi_remove(struct dw_hdmi *hdmi)
-{
-	drm_bridge_remove(&hdmi->bridge);
-
-	__dw_hdmi_remove(hdmi);
-}
 EXPORT_SYMBOL_GPL(dw_hdmi_remove);
 
 /* -----------------------------------------------------------------------------
@@ -3509,7 +3491,7 @@ struct dw_hdmi *dw_hdmi_bind(struct platform_device *pdev,
 	struct dw_hdmi *hdmi;
 	int ret;
 
-	hdmi = __dw_hdmi_probe(pdev, plat_data);
+	hdmi = dw_hdmi_probe(pdev, plat_data);
 	if (IS_ERR(hdmi))
 		return hdmi;
 
@@ -3526,7 +3508,7 @@ EXPORT_SYMBOL_GPL(dw_hdmi_bind);
 
 void dw_hdmi_unbind(struct dw_hdmi *hdmi)
 {
-	__dw_hdmi_remove(hdmi);
+	dw_hdmi_remove(hdmi);
 }
 EXPORT_SYMBOL_GPL(dw_hdmi_unbind);
 
-- 
2.7.4