linux-kernel - [PATCH v6 7/8] drm: zynqmp_dp: Take dp->lock in zynqmp_dp_hpd_work

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Message-Id: <20240809193600.3360015-8-sean.anderson@linux.dev>
Date: Fri,  9 Aug 2024 15:35:59 -0400
From: Sean Anderson <sean.anderson@...ux.dev>
To: Laurent Pinchart <laurent.pinchart@...asonboard.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	dri-devel@...ts.freedesktop.org
Cc: linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	David Airlie <airlied@...il.com>,
	Michal Simek <michal.simek@....com>,
	Daniel Vetter <daniel@...ll.ch>,
	Tomi Valkeinen <tomi.valkeinen@...asonboard.com>,
	Sean Anderson <sean.anderson@...ux.dev>
Subject: [PATCH v6 7/8] drm: zynqmp_dp: Take dp->lock in zynqmp_dp_hpd_work_func

Add a non-locking version of zynqmp_dp_bridge_detect and use it in
zynqmp_dp_hpd_work_func so we can take the lock explicitly. This will
make it easier to check for hpd_ignore when we add debugfs support.

Signed-off-by: Sean Anderson <sean.anderson@...ux.dev>
---

(no changes since v3)

Changes in v3:
- New

 drivers/gpu/drm/xlnx/zynqmp_dp.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
index e0ab3b3e8580..f5203ffa3c75 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
@@ -1567,14 +1567,13 @@ static int zynqmp_dp_bridge_atomic_check(struct drm_bridge *bridge,
 	return 0;
 }
 
-static enum drm_connector_status zynqmp_dp_bridge_detect(struct drm_bridge *bridge)
+static enum drm_connector_status __zynqmp_dp_bridge_detect(struct zynqmp_dp *dp)
 {
-	struct zynqmp_dp *dp = bridge_to_dp(bridge);
 	struct zynqmp_dp_link_config *link_config = &dp->link_config;
 	u32 state, i;
 	int ret;
 
-	mutex_lock(&dp->lock);
+	lockdep_assert_held(&dp->lock);
 
 	/*
 	 * This is from heuristic. It takes some delay (ex, 100 ~ 500 msec) to
@@ -1603,16 +1602,26 @@ static enum drm_connector_status zynqmp_dp_bridge_detect(struct drm_bridge *brid
 					       dp->num_lanes);
 
 		dp->status = connector_status_connected;
-		mutex_unlock(&dp->lock);
 		return connector_status_connected;
 	}
 
 disconnected:
 	dp->status = connector_status_disconnected;
-	mutex_unlock(&dp->lock);
 	return connector_status_disconnected;
 }
 
+static enum drm_connector_status zynqmp_dp_bridge_detect(struct drm_bridge *bridge)
+{
+	struct zynqmp_dp *dp = bridge_to_dp(bridge);
+	enum drm_connector_status ret;
+
+	mutex_lock(&dp->lock);
+	ret = __zynqmp_dp_bridge_detect(dp);
+	mutex_unlock(&dp->lock);
+
+	return ret;
+}
+
 static const struct drm_edid *zynqmp_dp_bridge_edid_read(struct drm_bridge *bridge,
 							 struct drm_connector *connector)
 {
@@ -1696,7 +1705,10 @@ static void zynqmp_dp_hpd_work_func(struct work_struct *work)
 	struct zynqmp_dp *dp = container_of(work, struct zynqmp_dp, hpd_work);
 	enum drm_connector_status status;
 
-	status = zynqmp_dp_bridge_detect(&dp->bridge);
+	mutex_lock(&dp->lock);
+	status = __zynqmp_dp_bridge_detect(dp);
+	mutex_unlock(&dp->lock);
+
 	drm_bridge_hpd_notify(&dp->bridge, status);
 }
 
-- 
2.35.1.1320.gc452695387.dirty