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From: Jai Luthra <j-luthra@ti.com>
Date: Thu, 22 Feb 2024 17:01:37 +0530
Subject: [PATCH RFC 21/21] media: ti: j721e-csi2rx: Submit all available
 buffers
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Message-ID: <20240222-multistream-v1-21-1837ed916eeb@ti.com>
References: <20240222-multistream-v1-0-1837ed916eeb@ti.com>
In-Reply-To: <20240222-multistream-v1-0-1837ed916eeb@ti.com>
To: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>,
        Mauro Carvalho Chehab
	<mchehab@kernel.org>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Hans
 Verkuil <hverkuil-cisco@xs4all.nl>,
        Vaishnav Achath <vaishnav.a@ti.com>,
        Maxime Ripard <mripard@kernel.org>, Rob Herring <robh@kernel.org>,
        Krzysztof
 Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley
	<conor+dt@kernel.org>
CC: <linux-media@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <devicetree@vger.kernel.org>, Vignesh Raghavendra <vigneshr@ti.com>,
        Aradhya
 Bhatia <a-bhatia1@ti.com>, Devarsh Thakkar <devarsht@ti.com>,
        Changhuang
 Liang <changhuang.liang@starfivetech.com>,
        Jack Zhu
	<jack.zhu@starfivetech.com>,
        Julien Massot <julien.massot@collabora.com>,
        Jayshri Pawar <jpawar@cadence.com>, Jai Luthra <j-luthra@ti.com>

We already make sure to submit all available buffers to DMA in each DMA
completion callback.

Move that logic in a separate function, and use it during stream start
as well, as most application queue all their buffers before stream on.

Signed-off-by: Jai Luthra <j-luthra@ti.com>
---
 .../media/platform/ti/j721e-csi2rx/j721e-csi2rx.c  | 43 ++++++++++++----------
 1 file changed, 24 insertions(+), 19 deletions(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index 0b9e0852da9f..a682db099e6c 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -666,6 +666,27 @@ static int ti_csi2rx_drain_dma(struct ti_csi2rx_ctx *ctx)
 	return ret;
 }
 
+static int ti_csi2rx_dma_submit_pending(struct ti_csi2rx_ctx *ctx)
+{
+	struct ti_csi2rx_dma *dma = &ctx->dma;
+	struct ti_csi2rx_buffer *buf;
+	int ret = 0;
+
+	/* If there are more buffers to process then start their transfer. */
+	while (!list_empty(&dma->queue)) {
+		buf = list_entry(dma->queue.next, struct ti_csi2rx_buffer, list);
+		ret = ti_csi2rx_start_dma(ctx, buf);
+		if (ret) {
+			dev_err(ctx->csi->dev,
+				"Failed to queue the next buffer for DMA\n");
+			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+			break;
+		}
+		list_move_tail(&buf->list, &dma->submitted);
+	}
+	return ret;
+}
+
 static void ti_csi2rx_dma_callback(void *param)
 {
 	struct ti_csi2rx_buffer *buf = param;
@@ -686,18 +707,7 @@ static void ti_csi2rx_dma_callback(void *param)
 	vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
 	list_del(&buf->list);
 
-	/* If there are more buffers to process then start their transfer. */
-	while (!list_empty(&dma->queue)) {
-		buf = list_entry(dma->queue.next, struct ti_csi2rx_buffer, list);
-
-		if (ti_csi2rx_start_dma(ctx, buf)) {
-			dev_err(ctx->csi->dev,
-				"Failed to queue the next buffer for DMA\n");
-			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
-		} else {
-			list_move_tail(&buf->list, &dma->submitted);
-		}
-	}
+	ti_csi2rx_dma_submit_pending(ctx);
 
 	if (list_empty(&dma->submitted))
 		dma->state = TI_CSI2RX_DMA_IDLE;
@@ -906,7 +916,6 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	struct ti_csi2rx_ctx *ctx = vb2_get_drv_priv(vq);
 	struct ti_csi2rx_dev *csi = ctx->csi;
 	struct ti_csi2rx_dma *dma = &ctx->dma;
-	struct ti_csi2rx_buffer *buf;
 	struct v4l2_subdev_krouting *routing;
 	struct v4l2_subdev_route *route = NULL;
 	struct media_pad *remote_pad;
@@ -972,16 +981,13 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	ctx->sequence = 0;
 
 	spin_lock_irqsave(&dma->lock, flags);
-	buf = list_entry(dma->queue.next, struct ti_csi2rx_buffer, list);
 
-	ret = ti_csi2rx_start_dma(ctx, buf);
+	ret = ti_csi2rx_dma_submit_pending(ctx);
 	if (ret) {
-		dev_err(csi->dev, "Failed to start DMA: %d\n", ret);
 		spin_unlock_irqrestore(&dma->lock, flags);
-		goto err_pipeline;
+		goto err_dma;
 	}
 
-	list_move_tail(&buf->list, &dma->submitted);
 	dma->state = TI_CSI2RX_DMA_ACTIVE;
 	spin_unlock_irqrestore(&dma->lock, flags);
 
@@ -995,7 +1001,6 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 
 err_dma:
 	ti_csi2rx_stop_dma(ctx);
-err_pipeline:
 	video_device_pipeline_stop(&ctx->vdev);
 	writel(0, csi->shim + SHIM_CNTL);
 	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));

-- 
2.43.0