msm: camera_v2: Fix page fault issue in camera ISP

Fix page fault in ISP when there is no reg update
for two consecutive request frame time.

Change-Id: Ie246f146c1ec0785e0e6fa0671dd2ff28fbe6b38
Signed-off-by: Lokesh Kumar Aakulu <lkumar@codeaurora.org>
Signed-off-by: Sumalatha Malothu <smalot@codeaurora.org>

2 files changed, 72 insertions, 2 deletions

diff --git a/drivers/media/platform/msm/camera_v2/isp/msm_isp.h b/drivers/media/platform/msm/camera_v2/isp/msm_isp.h
index cef2cd9ffcf1..a6fbb4102c2c 100644
--- a/drivers/media/platform/msm/camera_v2/isp/msm_isp.h
+++ b/drivers/media/platform/msm/camera_v2/isp/msm_isp.h
@@ -416,6 +416,12 @@ enum msm_isp_comp_irq_types {
 
 #define MSM_VFE_REQUESTQ_SIZE 8
 
+struct msm_isp_pending_buf_info {
+	uint32_t is_buf_done_pending;
+	struct msm_isp_buffer *buf;
+	uint32_t frame_id;
+};
+
 struct msm_vfe_axi_stream {
 	uint32_t frame_id;
 	enum msm_vfe_axi_state state;
@@ -472,6 +478,7 @@ struct msm_vfe_axi_stream {
 	uint32_t vfe_mask;
 	uint32_t composite_irq[MSM_ISP_COMP_IRQ_MAX];
 	int lpm_mode;
+	struct msm_isp_pending_buf_info pending_buf_info;
 };
 
 struct msm_vfe_axi_composite_info {
diff --git a/drivers/media/platform/msm/camera_v2/isp/msm_isp_axi_util.c b/drivers/media/platform/msm/camera_v2/isp/msm_isp_axi_util.c
index 011a1d4019eb..d498ef0ae7a6 100644
--- a/drivers/media/platform/msm/camera_v2/isp/msm_isp_axi_util.c
+++ b/drivers/media/platform/msm/camera_v2/isp/msm_isp_axi_util.c
@@ -27,6 +27,13 @@ static void __msm_isp_axi_stream_update(
 			struct msm_vfe_axi_stream *stream_info,
 			struct msm_isp_timestamp *ts);
 
+static int msm_isp_process_done_buf(struct vfe_device *vfe_dev,
+	struct msm_vfe_axi_stream *stream_info, struct msm_isp_buffer *buf,
+	struct timeval *time_stamp, uint32_t frame_id);
+static void msm_isp_free_pending_buffer(
+	struct vfe_device *vfe_dev,
+	struct msm_vfe_axi_stream *stream_info,
+	struct msm_isp_timestamp *ts);
 static int msm_isp_update_stream_bandwidth(
 		struct msm_vfe_axi_stream *stream_info, int enable);
 
@@ -659,6 +666,10 @@ void msm_isp_process_reg_upd_epoch_irq(struct vfe_device *vfe_dev,
 		case MSM_ISP_COMP_IRQ_REG_UPD:
 			stream_info->activated_framedrop_period =
 				stream_info->requested_framedrop_period;
+			/* Free Pending Buffers which are backed-up due to
+			 * delay in RUP from userspace to Avoid pageFault
+			 */
+			msm_isp_free_pending_buffer(vfe_dev, stream_info, ts);
 			__msm_isp_axi_stream_update(stream_info, ts);
 			break;
 		case MSM_ISP_COMP_IRQ_EPOCH:
@@ -1523,6 +1534,40 @@ static void msm_isp_axi_stream_enable_cfg(
 	}
 }
 
+static void msm_isp_free_pending_buffer(
+			struct vfe_device *vfe_dev,
+			struct msm_vfe_axi_stream *stream_info,
+			struct msm_isp_timestamp *ts)
+{
+	struct timeval *time_stamp;
+	struct msm_isp_buffer *done_buf = NULL;
+	uint32_t frame_id;
+	int rc;
+
+	if (!stream_info->controllable_output ||
+		!stream_info->pending_buf_info.is_buf_done_pending)	{
+		return;
+	}
+
+	if (vfe_dev->vt_enable) {
+		msm_isp_get_avtimer_ts(ts);
+		time_stamp = &ts->vt_time;
+	} else {
+		time_stamp = &ts->buf_time;
+	}
+
+	done_buf = stream_info->pending_buf_info.buf;
+	frame_id = stream_info->pending_buf_info.frame_id;
+	if (done_buf) {
+		rc = msm_isp_process_done_buf(vfe_dev, stream_info,
+			done_buf, time_stamp, frame_id);
+		if (rc == 0) {
+			stream_info->pending_buf_info.buf = NULL;
+			stream_info->pending_buf_info.is_buf_done_pending = 0;
+		}
+	}
+}
+
 static void __msm_isp_axi_stream_update(
 			struct msm_vfe_axi_stream *stream_info,
 			struct msm_isp_timestamp *ts)
@@ -3015,6 +3060,12 @@ static void __msm_isp_stop_axi_streams(struct vfe_device *vfe_dev,
 		msm_isp_cfg_stream_scratch(stream_info, VFE_PONG_FLAG);
 		stream_info->undelivered_request_cnt = 0;
 		vfe_dev->irq_sof_id = 0;
+		if (stream_info->controllable_output &&
+			stream_info->pending_buf_info.is_buf_done_pending) {
+			msm_isp_free_pending_buffer(vfe_dev, stream_info,
+				&timestamp);
+			stream_info->pending_buf_info.is_buf_done_pending = 0;
+		}
 		for (k = 0; k < stream_info->num_isp; k++) {
 			vfe_dev = stream_info->vfe_dev[k];
 			if (stream_info->num_planes > 1)
@@ -4349,9 +4400,21 @@ void msm_isp_process_axi_irq_stream(struct vfe_device *vfe_dev,
 		}
 		spin_unlock_irqrestore(&stream_info->lock, flags);
 	} else {
+		/* If there is no regupdate from userspace then dont
+		 * free buffer immediately, delegate it to RegUpdateAck
+		 */
+		if (stream_info->controllable_output &&
+			!(vfe_dev->reg_update_requested &
+				BIT((uint32_t)VFE_PIX_0))) {
+			stream_info->pending_buf_info.is_buf_done_pending = 1;
+			stream_info->pending_buf_info.buf = done_buf;
+			stream_info->pending_buf_info.frame_id = frame_id;
+		}
 		spin_unlock_irqrestore(&stream_info->lock, flags);
-		msm_isp_process_done_buf(vfe_dev, stream_info,
-			done_buf, time_stamp, frame_id);
+		if (stream_info->pending_buf_info.is_buf_done_pending != 1) {
+			msm_isp_process_done_buf(vfe_dev, stream_info,
+				done_buf, time_stamp, frame_id);
+		}
 	}
 }