video: driver: handle race between streamoff and qbuf sequence

Currently stramoff releases inst->lock and waits for response from
firmware i.e race issue. Streamoff released int->lock and that got
acquired by qbuf. So 2 FTB's were queued to firmware after streamoff
request.

Receiving qbuf after streamoff is treated as fatal at firmware side
and it sends session error as response to host. Added change to
avoid such issues.

Change-Id: I6da8ac0d3d30b540784e3c03c423270cb5212af2
Signed-off-by: Govindaraj Rajagopal <[email protected]>

driver/vidc/inc/msm_vidc_driver.h

@@ -293,7 +293,7 @@ enum msm_vidc_allow msm_vidc_allow_stop(struct msm_vidc_inst *inst);
 bool msm_vidc_allow_start(struct msm_vidc_inst *inst);
 bool msm_vidc_allow_streamon(struct msm_vidc_inst *inst, u32 type);
 bool msm_vidc_allow_streamoff(struct msm_vidc_inst *inst, u32 type);
-bool msm_vidc_allow_qbuf(struct msm_vidc_inst *inst);
+enum msm_vidc_allow msm_vidc_allow_qbuf(struct msm_vidc_inst *inst, u32 type);
 enum msm_vidc_allow msm_vidc_allow_input_psc(struct msm_vidc_inst *inst);
 bool msm_vidc_allow_last_flag(struct msm_vidc_inst *inst);
 int msm_vidc_state_change_streamon(struct msm_vidc_inst *inst, u32 type);

driver/vidc/src/msm_vidc.c

@@ -442,7 +442,7 @@ int msm_vidc_qbuf(void *instance, struct media_device *mdev,
 
 	mutex_lock(&inst->lock);
 
-	if (!msm_vidc_allow_qbuf(inst)) {
+	if (is_session_error(inst)) {
 		rc = -EBUSY;
 		goto unlock;
 	}

driver/vidc/src/msm_vidc_driver.c

@@ -1022,18 +1022,38 @@ bool msm_vidc_allow_streamoff(struct msm_vidc_inst *inst, u32 type)
 	return allow;
 }
 
-bool msm_vidc_allow_qbuf(struct msm_vidc_inst *inst)
+enum msm_vidc_allow msm_vidc_allow_qbuf(struct msm_vidc_inst *inst, u32 type)
 {
 	if (!inst) {
 		d_vpr_e("%s: invalid params\n", __func__);
-		return false;
+		return MSM_VIDC_DISALLOW;
 	}
 	if (inst->state == MSM_VIDC_ERROR) {
 		i_vpr_e(inst, "%s: inst in error state\n", __func__);
-		return false;
+		return MSM_VIDC_DISALLOW;
+	}
+	if (type == INPUT_META_PLANE || type == OUTPUT_META_PLANE)
+		return MSM_VIDC_DEFER;
+
+	if (type == INPUT_MPLANE) {
+		if (inst->state == MSM_VIDC_OPEN ||
+			inst->state == MSM_VIDC_START_OUTPUT)
+			return MSM_VIDC_DEFER;
+		else
+			return MSM_VIDC_ALLOW;
+	} else if (type == OUTPUT_MPLANE) {
+		if (inst->state == MSM_VIDC_OPEN ||
+			inst->state == MSM_VIDC_START_INPUT ||
+			inst->state == MSM_VIDC_DRAIN_START_INPUT)
+			return MSM_VIDC_DEFER;
+		else
+			return MSM_VIDC_ALLOW;
 	} else {
-		return true;
+		i_vpr_e(inst, "%s: unknown buffer type %d\n", __func__, type);
+		return MSM_VIDC_DISALLOW;
 	}
+
+	return MSM_VIDC_DISALLOW;
 }
 
 enum msm_vidc_allow msm_vidc_allow_input_psc(struct msm_vidc_inst *inst)
@@ -1730,6 +1750,7 @@ int msm_vidc_queue_buffer(struct msm_vidc_inst *inst, struct vb2_buffer *vb2)
 	int rc = 0;
 	struct msm_vidc_buffer *buf;
 	struct msm_vidc_buffer *meta;
+	enum msm_vidc_allow allow;
 	int port;
 
 	if (!inst || !vb2) {
@@ -1741,20 +1762,18 @@ int msm_vidc_queue_buffer(struct msm_vidc_inst *inst, struct vb2_buffer *vb2)
 	if (!buf)
 		return -EINVAL;
 
-	/* meta buffer will be queued along with actual buffer */
-	if (buf->type == MSM_VIDC_BUF_INPUT_META ||
-	    buf->type == MSM_VIDC_BUF_OUTPUT_META) {
-		buf->attr |= MSM_VIDC_ATTR_DEFERRED;
-		i_vpr_h(inst, "%s: %s_META qbuf deferred\n", __func__,
-			buf->type == MSM_VIDC_BUF_INPUT_META ? "INPUT" : "OUTPUT");
-		return 0;
-	}
-
 	/* skip queuing if streamon not completed */
 	port = v4l2_type_to_driver_port(inst, vb2->type, __func__);
 	if (port < 0)
 		return -EINVAL;
-	if (!inst->vb2q[port].streaming) {
+
+	allow = msm_vidc_allow_qbuf(inst, vb2->type);
+	if (allow == MSM_VIDC_DISALLOW) {
+		i_vpr_e(inst, "%s: qbuf not allowed\n", __func__);
+		return -EINVAL;
+	}
+
+	if (!inst->vb2q[port].streaming || allow == MSM_VIDC_DEFER) {
 		buf->attr |= MSM_VIDC_ATTR_DEFERRED;
 		print_vidc_buffer(VIDC_HIGH, "high", "qbuf deferred", inst, buf);
 		return 0;