6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Pin-yen Lin <treapking@xxxxxxxxxxxx>
[ Upstream commit 26db46bc9c675e43230cc6accd110110a7654299 ]
The ps8640 bridge seems to expect everything to be power cycled at the
disable process, but sometimes ps8640_aux_transfer() holds the runtime
PM reference and prevents the bridge from suspend.
Prevent that by introducing a mutex lock between ps8640_aux_transfer()
and .post_disable() to make sure the bridge is really powered off.
Fixes: 826cff3f7ebb ("drm/bridge: parade-ps8640: Enable runtime power management")
Signed-off-by: Pin-yen Lin <treapking@xxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20240109120528.1292601-1-treapking@xxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/bridge/parade-ps8640.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
index fb5e9ae9ad81..166bfc725ef4 100644
--- a/drivers/gpu/drm/bridge/parade-ps8640.c
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -107,6 +107,7 @@ struct ps8640 {
struct device_link *link;
bool pre_enabled;
bool need_post_hpd_delay;
+ struct mutex aux_lock;
};
static const struct regmap_config ps8640_regmap_config[] = {
@@ -345,6 +346,7 @@ static ssize_t ps8640_aux_transfer(struct drm_dp_aux *aux,
struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
int ret;
+ mutex_lock(&ps_bridge->aux_lock);
pm_runtime_get_sync(dev);
ret = _ps8640_wait_hpd_asserted(ps_bridge, 200 * 1000);
if (ret) {
@@ -354,6 +356,7 @@ static ssize_t ps8640_aux_transfer(struct drm_dp_aux *aux,
ret = ps8640_aux_transfer_msg(aux, msg);
pm_runtime_mark_last_busy(dev);
pm_runtime_put_autosuspend(dev);
+ mutex_unlock(&ps_bridge->aux_lock);
return ret;
}
@@ -475,7 +478,18 @@ static void ps8640_atomic_post_disable(struct drm_bridge *bridge,
ps_bridge->pre_enabled = false;
ps8640_bridge_vdo_control(ps_bridge, DISABLE);
+
+ /*
+ * The bridge seems to expect everything to be power cycled at the
+ * disable process, so grab a lock here to make sure
+ * ps8640_aux_transfer() is not holding a runtime PM reference and
+ * preventing the bridge from suspend.
+ */
+ mutex_lock(&ps_bridge->aux_lock);
+
pm_runtime_put_sync_suspend(&ps_bridge->page[PAGE0_DP_CNTL]->dev);
+
+ mutex_unlock(&ps_bridge->aux_lock);
}
static int ps8640_bridge_attach(struct drm_bridge *bridge,
@@ -624,6 +638,8 @@ static int ps8640_probe(struct i2c_client *client)
if (!ps_bridge)
return -ENOMEM;
+ mutex_init(&ps_bridge->aux_lock);
+
ps_bridge->supplies[0].supply = "vdd12";
ps_bridge->supplies[1].supply = "vdd33";
ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ps_bridge->supplies),
--
2.43.0
