[PATCH 4/6] drm/rockchip: Improve analogix-dp psr handling

[Sean Paul]

Remove the delayed worker, opting instead for the non-delayed
variety. Also introduce a lock to ensure we don't have races
with the worker and psr_state. Finally, cancel and wait for
the worker to finish when disabling the bridge.

Signed-off-by: Sean Paul <seanpaul at chromium.org>
---
 drivers/gpu/drm/bridge/analogix/analogix_dp_core.c |  1 -
 drivers/gpu/drm/rockchip/analogix_dp-rockchip.c    | 24 ++++++++++++++--------
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index 6a5dd84..2f4d76b 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -105,7 +105,6 @@ int analogix_dp_enable_psr(struct device *dev)
 	if (!dp->psr_support)
 		return -EINVAL;
 
-
 	/* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
 	memset(&psr_vsc, 0, sizeof(psr_vsc));
 	psr_vsc.sdp_header.HB0 = 0;
diff --git a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
index 9586de2..8c44dba 100644
--- a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
@@ -35,7 +35,6 @@
 #include "rockchip_drm_psr.h"
 #include "rockchip_drm_vop.h"
 
-#define PSR_SET_DELAY_TIME		msecs_to_jiffies(10)
 #define PSR_WAIT_LINE_FLAG_TIMEOUT_MS	100
 
 #define to_dp(nm)	container_of(nm, struct rockchip_dp_device, nm)
@@ -64,7 +63,8 @@ struct rockchip_dp_device {
 	struct regmap            *grf;
 	struct reset_control     *rst;
 
-	struct delayed_work      psr_work;
+	struct work_struct	 psr_work;
+	spinlock_t		 psr_lock;
 	unsigned int             psr_state;
 
 	const struct rockchip_dp_chip_data *data;
@@ -75,30 +75,34 @@ struct rockchip_dp_device {
 static void analogix_dp_psr_set(struct drm_encoder *encoder, bool enabled)
 {
 	struct rockchip_dp_device *dp = to_dp(encoder);
+	unsigned long flags;
 
 	dev_dbg(dp->dev, "%s PSR...\n", enabled ? "Entry" : "Exit");
 
+	spin_lock_irqsave(&dp->psr_lock, flags);
 	if (enabled)
 		dp->psr_state = EDP_VSC_PSR_STATE_ACTIVE;
 	else
 		dp->psr_state = ~EDP_VSC_PSR_STATE_ACTIVE;
 
-	schedule_delayed_work(&dp->psr_work, PSR_SET_DELAY_TIME);
+	schedule_work(&dp->psr_work);
+	spin_unlock_irqrestore(&dp->psr_lock, flags);
 }
 
 static void analogix_dp_psr_work(struct work_struct *work)
 {
 	struct rockchip_dp_device *dp =
-				container_of(work, typeof(*dp), psr_work.work);
+				container_of(work, typeof(*dp), psr_work);
 	struct drm_crtc *crtc = dp->encoder.crtc;
-	int psr_state = dp->psr_state;
 	int vact_end;
 	int ret;
+	unsigned long flags;
 
 	if (!crtc)
 		return;
 
-	vact_end = crtc->mode.vtotal - crtc->mode.vsync_start + crtc->mode.vdisplay;
+	vact_end = crtc->mode.vtotal - crtc->mode.vsync_start +
+			crtc->mode.vdisplay;
 
 	ret = rockchip_drm_wait_line_flag(dp->encoder.crtc, vact_end,
 					  PSR_WAIT_LINE_FLAG_TIMEOUT_MS);
@@ -107,10 +111,12 @@ static void analogix_dp_psr_work(struct work_struct *work)
 		return;
 	}
 
-	if (psr_state == EDP_VSC_PSR_STATE_ACTIVE)
+	spin_lock_irqsave(&dp->psr_lock, flags);
+	if (dp->psr_state == EDP_VSC_PSR_STATE_ACTIVE)
 		analogix_dp_enable_psr(dp->dev);
 	else
 		analogix_dp_disable_psr(dp->dev);
+	spin_unlock_irqrestore(&dp->psr_lock, flags);
 }
 
 static int rockchip_dp_pre_init(struct rockchip_dp_device *dp)
@@ -146,6 +152,7 @@ static int rockchip_dp_powerdown(struct analogix_dp_plat_data *plat_data)
 {
 	struct rockchip_dp_device *dp = to_dp(plat_data);
 
+	cancel_work_sync(&dp->psr_work);
 	clk_disable_unprepare(dp->pclk);
 
 	return 0;
@@ -390,8 +397,9 @@ static int rockchip_dp_bind(struct device *dev, struct device *master,
 	dp->plat_data.power_off = rockchip_dp_powerdown;
 	dp->plat_data.get_modes = rockchip_dp_get_modes;
 
+	spin_lock_init(&dp->psr_lock);
 	dp->psr_state = ~EDP_VSC_PSR_STATE_ACTIVE;
-	INIT_DELAYED_WORK(&dp->psr_work, analogix_dp_psr_work);
+	INIT_WORK(&dp->psr_work, analogix_dp_psr_work);
 
 	rockchip_drm_psr_register(&dp->encoder, analogix_dp_psr_set);
 
-- 
2.8.0.rc3.226.g39d4020