[PATCH v3 04/12] media: staging: rkisp1: params: avoid using buffer if params is not streaming

[Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>]

Currently, the first buffer queued in the params node is returned
immediately to userspace and a copy of it is saved in the field
'cur_params'. The copy is later used for the first configuration
when the stream is initiated by one of selfpath/mainpath capture nodes.

There are 3 problems with this implementation:
- The first params buffer is applied and returned to userspace even if
userspace never calls to streamon on the params node.
- If the first params buffer is queued after the stream started on the
params node then it will return to userspace but will never be used.
- The frame_sequence of the first buffer is set to -1 if the main/selfpath
did not start streaming.

A correct implementation is to apply the first params buffer when stream
is started from mainpath/selfpath and only if params is also streaming.

The patch adds a new function 'rkisp1_params_apply_params_cfg' which takes
a buffer from the buffers queue, apply it and returns it to userspace.
The function is called from the irq handler and when main/selfpath stream
starts - in the function 'rkisp1_params_config_parameter'

Also remove the fields 'cur_params', 'is_first_params' which are no
more needed.

Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Acked-by: Helen Koike <helen.koike@xxxxxxxxxxxxx>
---
changes since v2:
declare function 'rkisp1_params_apply_params_cfg' as static
to fix a warning reported by 'kernel test robot <lkp@xxxxxxxxx>'
---
 drivers/staging/media/rkisp1/rkisp1-common.h |  4 --
 drivers/staging/media/rkisp1/rkisp1-params.c | 50 ++++++++------------
 2 files changed, 20 insertions(+), 34 deletions(-)

diff --git a/drivers/staging/media/rkisp1/rkisp1-common.h b/drivers/staging/media/rkisp1/rkisp1-common.h
index 992d8ec4c448..232bee92d0eb 100644
--- a/drivers/staging/media/rkisp1/rkisp1-common.h
+++ b/drivers/staging/media/rkisp1/rkisp1-common.h
@@ -262,10 +262,8 @@ struct rkisp1_stats {
  * @rkisp1:		pointer to the rkisp1 device
  * @config_lock:	locks the buffer list 'params' and 'is_streaming'
  * @params:		queue of rkisp1_buffer
- * @cur_params:		the first params values from userspace
  * @vdev_fmt:		v4l2_format of the metadata format
  * @is_streaming:	device is streaming
- * @is_first_params:	the first params should take effect immediately
  * @quantization:	the quantization configured on the isp's src pad
  * @raw_type:		the bayer pattern on the isp video sink pad
  */
@@ -275,10 +273,8 @@ struct rkisp1_params {
 
 	spinlock_t config_lock; /* locks the buffers list 'params' and 'is_streaming' */
 	struct list_head params;
-	struct rkisp1_params_cfg cur_params;
 	struct v4l2_format vdev_fmt;
 	bool is_streaming;
-	bool is_first_params;
 
 	enum v4l2_quantization quantization;
 	enum rkisp1_fmt_raw_pat_type raw_type;
diff --git a/drivers/staging/media/rkisp1/rkisp1-params.c b/drivers/staging/media/rkisp1/rkisp1-params.c
index ab2deb57b1eb..e8049a50575f 100644
--- a/drivers/staging/media/rkisp1/rkisp1-params.c
+++ b/drivers/staging/media/rkisp1/rkisp1-params.c
@@ -1185,23 +1185,14 @@ static void rkisp1_isp_isr_meas_config(struct rkisp1_params *params,
 	}
 }
 
-void rkisp1_params_isr(struct rkisp1_device *rkisp1)
+static void rkisp1_params_apply_params_cfg(struct rkisp1_params *params,
+					   unsigned int frame_sequence)
 {
-	unsigned int frame_sequence = atomic_read(&rkisp1->isp.frame_sequence);
-	struct rkisp1_params *params = &rkisp1->params;
 	struct rkisp1_params_cfg *new_params;
 	struct rkisp1_buffer *cur_buf = NULL;
 
-	spin_lock(&params->config_lock);
-	if (!params->is_streaming) {
-		spin_unlock(&params->config_lock);
-		return;
-	}
-
-	if (list_empty(&params->params)) {
-		spin_unlock(&params->config_lock);
+	if (list_empty(&params->params))
 		return;
-	}
 
 	cur_buf = list_first_entry(&params->params,
 				   struct rkisp1_buffer, queue);
@@ -1218,6 +1209,20 @@ void rkisp1_params_isr(struct rkisp1_device *rkisp1)
 
 	cur_buf->vb.sequence = frame_sequence;
 	vb2_buffer_done(&cur_buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
+}
+
+void rkisp1_params_isr(struct rkisp1_device *rkisp1)
+{
+	unsigned int frame_sequence = atomic_read(&rkisp1->isp.frame_sequence);
+	struct rkisp1_params *params = &rkisp1->params;
+
+	spin_lock(&params->config_lock);
+	if (!params->is_streaming) {
+		spin_unlock(&params->config_lock);
+		return;
+	}
+	rkisp1_params_apply_params_cfg(params, frame_sequence);
+
 	spin_unlock(&params->config_lock);
 }
 
@@ -1290,9 +1295,9 @@ static void rkisp1_params_config_parameter(struct rkisp1_params *params)
 	else
 		rkisp1_csm_config(params, false);
 
-	/* override the default things */
-	rkisp1_isp_isr_other_config(params, &params->cur_params);
-	rkisp1_isp_isr_meas_config(params, &params->cur_params);
+	/* apply the first buffer if there is one already */
+	if (params->is_streaming)
+		rkisp1_params_apply_params_cfg(params, 0);
 
 	spin_unlock(&params->config_lock);
 }
@@ -1420,8 +1425,6 @@ static int rkisp1_params_vb2_queue_setup(struct vb2_queue *vq,
 	sizes[0] = sizeof(struct rkisp1_params_cfg);
 
 	INIT_LIST_HEAD(&params->params);
-	params->is_first_params = true;
-
 	return 0;
 }
 
@@ -1432,20 +1435,7 @@ static void rkisp1_params_vb2_buf_queue(struct vb2_buffer *vb)
 		container_of(vbuf, struct rkisp1_buffer, vb);
 	struct vb2_queue *vq = vb->vb2_queue;
 	struct rkisp1_params *params = vq->drv_priv;
-	struct rkisp1_params_cfg *new_params;
 	unsigned long flags;
-	unsigned int frame_sequence =
-		atomic_read(&params->rkisp1->isp.frame_sequence);
-
-	if (params->is_first_params) {
-		new_params = (struct rkisp1_params_cfg *)
-			(vb2_plane_vaddr(vb, 0));
-		vbuf->sequence = frame_sequence;
-		vb2_buffer_done(&params_buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
-		params->is_first_params = false;
-		params->cur_params = *new_params;
-		return;
-	}
 
 	params_buf->vaddr = vb2_plane_vaddr(vb, 0);
 	spin_lock_irqsave(&params->config_lock, flags);
-- 
2.17.1