[PATCH] drm/bridge: analogix_dp: detect Sink PSR state after configuring the PSR

[Yakir Yang <ykk@xxxxxxxxxxxxxx>]

Make sure the request PSR state could effect in analogix_dp_send_psr_spd()
function, or printing the error Sink PSR state if we failed to effect
the request PSR setting.

Signed-off-by: Yakir Yang <ykk@xxxxxxxxxxxxxx>
---
 drivers/gpu/drm/bridge/analogix/analogix_dp_core.c |  6 ++---
 drivers/gpu/drm/bridge/analogix/analogix_dp_core.h |  4 ++--
 drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c  | 26 ++++++++++++++++++++--
 3 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index efac8ab..5a37de8 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -115,8 +115,7 @@ int analogix_dp_enable_psr(struct device *dev)
 	psr_vsc.DB0 = 0;
 	psr_vsc.DB1 = EDP_VSC_PSR_STATE_ACTIVE | EDP_VSC_PSR_CRC_VALUES_VALID;
 
-	analogix_dp_send_psr_spd(dp, &psr_vsc);
-	return 0;
+	return analogix_dp_send_psr_spd(dp, &psr_vsc);
 }
 EXPORT_SYMBOL_GPL(analogix_dp_enable_psr);
 
@@ -138,8 +137,7 @@ int analogix_dp_disable_psr(struct device *dev)
 	psr_vsc.DB0 = 0;
 	psr_vsc.DB1 = 0;
 
-	analogix_dp_send_psr_spd(dp, &psr_vsc);
-	return 0;
+	return analogix_dp_send_psr_spd(dp, &psr_vsc);
 }
 EXPORT_SYMBOL_GPL(analogix_dp_disable_psr);
 
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
index 473b980..f617a9d 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
@@ -283,7 +283,7 @@ void analogix_dp_config_video_slave_mode(struct analogix_dp_device *dp);
 void analogix_dp_enable_scrambling(struct analogix_dp_device *dp);
 void analogix_dp_disable_scrambling(struct analogix_dp_device *dp);
 void analogix_dp_enable_psr_crc(struct analogix_dp_device *dp);
-void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
-			      struct edp_vsc_psr *vsc);
+int analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
+			     struct edp_vsc_psr *vsc);
 
 #endif /* _ANALOGIX_DP_CORE_H */
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
index 52c1b6b..505e9d8 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
@@ -1328,9 +1328,11 @@ void analogix_dp_enable_psr_crc(struct analogix_dp_device *dp)
 	writel(PSR_VID_CRC_ENABLE, dp->reg_base + ANALOGIX_DP_CRC_CON);
 }
 
-void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
-			      struct edp_vsc_psr *vsc)
+int analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
+			     struct edp_vsc_psr *vsc)
 {
+	unsigned long timeout;
+	unsigned char sink;
 	unsigned int val;
 
 	/* don't send info frame */
@@ -1372,4 +1374,24 @@ void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
 	val = readl(dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
 	val |= IF_EN;
 	writel(val, dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
+
+	timeout = jiffies + msecs_to_jiffies(100);
+	while (1) {
+		analogix_dp_read_byte_from_dpcd(dp, DP_PSR_STATUS, &sink);
+
+		if (vsc->DB1 && sink == DP_PSR_SINK_ACTIVE_RFB)
+			break;
+
+		if (!vsc->DB1 && sink == DP_PSR_SINK_INACTIVE)
+			break;
+
+		if (time_after(jiffies, timeout)) {
+			dev_warn(dp->dev, "Failed to effect PSR: %x", sink);
+			return -EBUSY;
+		}
+
+		usleep_range(1000, 1500);
+	}
+
+	return 0;
 }
-- 
1.9.1


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