[PATCH v2 0/5] media: ti: cal: misc fixes

[PATCH v2 0/5] media: ti: cal: misc fixes

[Tomi Valkeinen]

Hi,

v2 of the series. v1 can be found from:

https://lore.kernel.org/all/20220421143449.552312-1-tomi.valkeinen@ideasonboard.com/

Changes in v2:

- Drop "media: ti: cal: fix error paths in cal_camerarx_create()"
- Improved descs in "media: ti: cal: rename sd_state to state" and
  "media: ti: cal: use CSI-2 frame number for seq number"

 Tomi

Tomi Valkeinen (5):
  media: ti: cal: fix useless variable init
  media: ti: cal: rename sd_state to state
  media: ti: cal: use CSI-2 frame number for seq number
  media: ti: cal: combine wdma irq handling
  media: ti: cal: fix wdma irq for metadata

 drivers/media/platform/ti/cal/cal-camerarx.c |  31 +++--
 drivers/media/platform/ti/cal/cal-video.c    |   5 +-
 drivers/media/platform/ti/cal/cal.c          | 139 ++++++++++++++-----
 drivers/media/platform/ti/cal/cal.h          |   7 +-
 4 files changed, 128 insertions(+), 54 deletions(-)

-- 
2.34.1

[PATCH v2 1/5] media: ti: cal: fix useless variable init

[Tomi Valkeinen]

'ret' is initialized needlessly in cal_legacy_try_fmt_vid_cap(). We can
also move the variable to the for block, which is the only place where
it is used.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/platform/ti/cal/cal-video.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/ti/cal/cal-video.c b/drivers/media/platform/ti/cal/cal-video.c
index 3e936a2ca36c..1cbd9bda1892 100644
--- a/drivers/media/platform/ti/cal/cal-video.c
+++ b/drivers/media/platform/ti/cal/cal-video.c
@@ -195,7 +195,7 @@ static int cal_legacy_try_fmt_vid_cap(struct file *file, void *priv,
 	struct cal_ctx *ctx = video_drvdata(file);
 	const struct cal_format_info *fmtinfo;
 	struct v4l2_subdev_frame_size_enum fse;
-	int ret, found;
+	int found;
 
 	fmtinfo = find_format_by_pix(ctx, f->fmt.pix.pixelformat);
 	if (!fmtinfo) {
@@ -210,12 +210,13 @@ static int cal_legacy_try_fmt_vid_cap(struct file *file, void *priv,
 	f->fmt.pix.field = ctx->v_fmt.fmt.pix.field;
 
 	/* check for/find a valid width/height */
-	ret = 0;
 	found = false;
 	fse.pad = 0;
 	fse.code = fmtinfo->code;
 	fse.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 	for (fse.index = 0; ; fse.index++) {
+		int ret;
+
 		ret = v4l2_subdev_call(ctx->phy->source, pad, enum_frame_size,
 				       NULL, &fse);
 		if (ret)
-- 
2.34.1

[PATCH v2 2/5] media: ti: cal: rename sd_state to state

[Tomi Valkeinen]

Rename 'sd_state' parameters to 'state'. There are no other states, so
there is no ambiguity.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/platform/ti/cal/cal-camerarx.c | 30 ++++++++++----------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/media/platform/ti/cal/cal-camerarx.c b/drivers/media/platform/ti/cal/cal-camerarx.c
index 6b43a1525b45..4469773f6eb9 100644
--- a/drivers/media/platform/ti/cal/cal-camerarx.c
+++ b/drivers/media/platform/ti/cal/cal-camerarx.c
@@ -595,12 +595,12 @@ static inline struct cal_camerarx *to_cal_camerarx(struct v4l2_subdev *sd)
 
 static struct v4l2_mbus_framefmt *
 cal_camerarx_get_pad_format(struct cal_camerarx *phy,
-			    struct v4l2_subdev_state *sd_state,
+			    struct v4l2_subdev_state *state,
 			    unsigned int pad, u32 which)
 {
 	switch (which) {
 	case V4L2_SUBDEV_FORMAT_TRY:
-		return v4l2_subdev_get_try_format(&phy->subdev, sd_state, pad);
+		return v4l2_subdev_get_try_format(&phy->subdev, state, pad);
 	case V4L2_SUBDEV_FORMAT_ACTIVE:
 		return &phy->formats[pad];
 	default:
@@ -626,7 +626,7 @@ static int cal_camerarx_sd_s_stream(struct v4l2_subdev *sd, int enable)
 }
 
 static int cal_camerarx_sd_enum_mbus_code(struct v4l2_subdev *sd,
-					  struct v4l2_subdev_state *sd_state,
+					  struct v4l2_subdev_state *state,
 					  struct v4l2_subdev_mbus_code_enum *code)
 {
 	struct cal_camerarx *phy = to_cal_camerarx(sd);
@@ -643,7 +643,7 @@ static int cal_camerarx_sd_enum_mbus_code(struct v4l2_subdev *sd,
 			goto out;
 		}
 
-		fmt = cal_camerarx_get_pad_format(phy, sd_state,
+		fmt = cal_camerarx_get_pad_format(phy, state,
 						  CAL_CAMERARX_PAD_SINK,
 						  code->which);
 		code->code = fmt->code;
@@ -663,7 +663,7 @@ static int cal_camerarx_sd_enum_mbus_code(struct v4l2_subdev *sd,
 }
 
 static int cal_camerarx_sd_enum_frame_size(struct v4l2_subdev *sd,
-					   struct v4l2_subdev_state *sd_state,
+					   struct v4l2_subdev_state *state,
 					   struct v4l2_subdev_frame_size_enum *fse)
 {
 	struct cal_camerarx *phy = to_cal_camerarx(sd);
@@ -679,7 +679,7 @@ static int cal_camerarx_sd_enum_frame_size(struct v4l2_subdev *sd,
 	if (cal_rx_pad_is_source(fse->pad)) {
 		struct v4l2_mbus_framefmt *fmt;
 
-		fmt = cal_camerarx_get_pad_format(phy, sd_state,
+		fmt = cal_camerarx_get_pad_format(phy, state,
 						  CAL_CAMERARX_PAD_SINK,
 						  fse->which);
 		if (fse->code != fmt->code) {
@@ -711,7 +711,7 @@ static int cal_camerarx_sd_enum_frame_size(struct v4l2_subdev *sd,
 }
 
 static int cal_camerarx_sd_get_fmt(struct v4l2_subdev *sd,
-				   struct v4l2_subdev_state *sd_state,
+				   struct v4l2_subdev_state *state,
 				   struct v4l2_subdev_format *format)
 {
 	struct cal_camerarx *phy = to_cal_camerarx(sd);
@@ -719,7 +719,7 @@ static int cal_camerarx_sd_get_fmt(struct v4l2_subdev *sd,
 
 	mutex_lock(&phy->mutex);
 
-	fmt = cal_camerarx_get_pad_format(phy, sd_state, format->pad,
+	fmt = cal_camerarx_get_pad_format(phy, state, format->pad,
 					  format->which);
 	format->format = *fmt;
 
@@ -729,7 +729,7 @@ static int cal_camerarx_sd_get_fmt(struct v4l2_subdev *sd,
 }
 
 static int cal_camerarx_sd_set_fmt(struct v4l2_subdev *sd,
-				   struct v4l2_subdev_state *sd_state,
+				   struct v4l2_subdev_state *state,
 				   struct v4l2_subdev_format *format)
 {
 	struct cal_camerarx *phy = to_cal_camerarx(sd);
@@ -739,7 +739,7 @@ static int cal_camerarx_sd_set_fmt(struct v4l2_subdev *sd,
 
 	/* No transcoding, source and sink formats must match. */
 	if (cal_rx_pad_is_source(format->pad))
-		return cal_camerarx_sd_get_fmt(sd, sd_state, format);
+		return cal_camerarx_sd_get_fmt(sd, state, format);
 
 	/*
 	 * Default to the first format if the requested media bus code isn't
@@ -765,12 +765,12 @@ static int cal_camerarx_sd_set_fmt(struct v4l2_subdev *sd,
 
 	mutex_lock(&phy->mutex);
 
-	fmt = cal_camerarx_get_pad_format(phy, sd_state,
+	fmt = cal_camerarx_get_pad_format(phy, state,
 					  CAL_CAMERARX_PAD_SINK,
 					  format->which);
 	*fmt = format->format;
 
-	fmt = cal_camerarx_get_pad_format(phy, sd_state,
+	fmt = cal_camerarx_get_pad_format(phy, state,
 					  CAL_CAMERARX_PAD_FIRST_SOURCE,
 					  format->which);
 	*fmt = format->format;
@@ -781,10 +781,10 @@ static int cal_camerarx_sd_set_fmt(struct v4l2_subdev *sd,
 }
 
 static int cal_camerarx_sd_init_cfg(struct v4l2_subdev *sd,
-				    struct v4l2_subdev_state *sd_state)
+				    struct v4l2_subdev_state *state)
 {
 	struct v4l2_subdev_format format = {
-		.which = sd_state ? V4L2_SUBDEV_FORMAT_TRY
+		.which = state ? V4L2_SUBDEV_FORMAT_TRY
 		: V4L2_SUBDEV_FORMAT_ACTIVE,
 		.pad = CAL_CAMERARX_PAD_SINK,
 		.format = {
@@ -799,7 +799,7 @@ static int cal_camerarx_sd_init_cfg(struct v4l2_subdev *sd,
 		},
 	};
 
-	return cal_camerarx_sd_set_fmt(sd, sd_state, &format);
+	return cal_camerarx_sd_set_fmt(sd, state, &format);
 }
 
 static const struct v4l2_subdev_video_ops cal_camerarx_video_ops = {
-- 
2.34.1

[PATCH v2 3/5] media: ti: cal: use CSI-2 frame number for seq number

[Tomi Valkeinen]

The userspace needs a way to match received metadata buffers to pixel
data buffers. The obvious way to do this is to use the CSI-2 frame
number, as both the metadata and the pixel data have the same frame
number as they come from the same frame.

However, we don't have means to convey the frame number to userspace. We
do have the 'sequence' field, which with a few tricks can be used for
this purpose.

To achieve this, track the frame number for each virtual channel and
increase the sequence for each virtual channel by frame-number -
previous-frame-number, also taking into account the eventual wrap of the
CSI-2 frame number. If the CSI-2 peripheral does not support frame
numbers, CAL increases the frame number register by one each frame.

This way we get a monotonically increasing sequence number which is
common to all streams using the same virtual channel.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/media/platform/ti/cal/cal-camerarx.c |  1 +
 drivers/media/platform/ti/cal/cal.c          | 57 +++++++++++++++++++-
 drivers/media/platform/ti/cal/cal.h          |  7 ++-
 3 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/ti/cal/cal-camerarx.c b/drivers/media/platform/ti/cal/cal-camerarx.c
index 4469773f6eb9..8206c172c63b 100644
--- a/drivers/media/platform/ti/cal/cal-camerarx.c
+++ b/drivers/media/platform/ti/cal/cal-camerarx.c
@@ -844,6 +844,7 @@ struct cal_camerarx *cal_camerarx_create(struct cal_dev *cal,
 	phy->cal = cal;
 	phy->instance = instance;
 
+	spin_lock_init(&phy->vc_lock);
 	mutex_init(&phy->mutex);
 
 	phy->res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
diff --git a/drivers/media/platform/ti/cal/cal.c b/drivers/media/platform/ti/cal/cal.c
index 4a4a6c5983f7..783ce5a8cd79 100644
--- a/drivers/media/platform/ti/cal/cal.c
+++ b/drivers/media/platform/ti/cal/cal.c
@@ -496,7 +496,22 @@ void cal_ctx_unprepare(struct cal_ctx *ctx)
 
 void cal_ctx_start(struct cal_ctx *ctx)
 {
-	ctx->sequence = 0;
+	struct cal_camerarx *phy = ctx->phy;
+
+	/*
+	 * Reset the frame number & sequence number, but only if the
+	 * virtual channel is not already in use.
+	 */
+
+	spin_lock(&phy->vc_lock);
+
+	if (phy->vc_enable_count[ctx->vc]++ == 0) {
+		phy->vc_frame_number[ctx->vc] = 0;
+		phy->vc_sequence[ctx->vc] = 0;
+	}
+
+	spin_unlock(&phy->vc_lock);
+
 	ctx->dma.state = CAL_DMA_RUNNING;
 
 	/* Configure the CSI-2, pixel processing and write DMA contexts. */
@@ -516,8 +531,15 @@ void cal_ctx_start(struct cal_ctx *ctx)
 
 void cal_ctx_stop(struct cal_ctx *ctx)
 {
+	struct cal_camerarx *phy = ctx->phy;
 	long timeout;
 
+	WARN_ON(phy->vc_enable_count[ctx->vc] == 0);
+
+	spin_lock(&phy->vc_lock);
+	phy->vc_enable_count[ctx->vc]--;
+	spin_unlock(&phy->vc_lock);
+
 	/*
 	 * Request DMA stop and wait until it completes. If completion times
 	 * out, forcefully disable the DMA.
@@ -554,6 +576,34 @@ void cal_ctx_stop(struct cal_ctx *ctx)
  * ------------------------------------------------------------------
  */
 
+/*
+ * Track a sequence number for each virtual channel, which is shared by
+ * all contexts using the same virtual channel. This is done using the
+ * CSI-2 frame number as a base.
+ */
+static void cal_update_seq_number(struct cal_ctx *ctx)
+{
+	struct cal_dev *cal = ctx->cal;
+	struct cal_camerarx *phy = ctx->phy;
+	u16 prev_frame_num, frame_num;
+	u8 vc = ctx->vc;
+
+	frame_num =
+		cal_read(cal, CAL_CSI2_STATUS(phy->instance, ctx->csi2_ctx)) &
+		0xffff;
+
+	if (phy->vc_frame_number[vc] != frame_num) {
+		prev_frame_num = phy->vc_frame_number[vc];
+
+		if (prev_frame_num >= frame_num)
+			phy->vc_sequence[vc] += 1;
+		else
+			phy->vc_sequence[vc] += frame_num - prev_frame_num;
+
+		phy->vc_frame_number[vc] = frame_num;
+	}
+}
+
 static inline void cal_irq_wdma_start(struct cal_ctx *ctx)
 {
 	spin_lock(&ctx->dma.lock);
@@ -584,6 +634,8 @@ static inline void cal_irq_wdma_start(struct cal_ctx *ctx)
 	}
 
 	spin_unlock(&ctx->dma.lock);
+
+	cal_update_seq_number(ctx);
 }
 
 static inline void cal_irq_wdma_end(struct cal_ctx *ctx)
@@ -610,7 +662,8 @@ static inline void cal_irq_wdma_end(struct cal_ctx *ctx)
 	if (buf) {
 		buf->vb.vb2_buf.timestamp = ktime_get_ns();
 		buf->vb.field = ctx->v_fmt.fmt.pix.field;
-		buf->vb.sequence = ctx->sequence++;
+		buf->vb.sequence = ctx->phy->vc_sequence[ctx->vc];
+
 		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
 	}
 }
diff --git a/drivers/media/platform/ti/cal/cal.h b/drivers/media/platform/ti/cal/cal.h
index 527e22d022f3..dfb628cd3bdd 100644
--- a/drivers/media/platform/ti/cal/cal.h
+++ b/drivers/media/platform/ti/cal/cal.h
@@ -180,6 +180,12 @@ struct cal_camerarx {
 	struct media_pad	pads[CAL_CAMERARX_NUM_PADS];
 	struct v4l2_mbus_framefmt	formats[CAL_CAMERARX_NUM_PADS];
 
+	/* protects the vc_* fields below */
+	spinlock_t		vc_lock;
+	u8			vc_enable_count[4];
+	u16			vc_frame_number[4];
+	u32			vc_sequence[4];
+
 	/*
 	 * Lock for camerarx ops. Protects:
 	 * - formats
@@ -242,7 +248,6 @@ struct cal_ctx {
 	const struct cal_format_info	**active_fmt;
 	unsigned int		num_active_fmt;
 
-	unsigned int		sequence;
 	struct vb2_queue	vb_vidq;
 	u8			dma_ctx;
 	u8			cport;
-- 
2.34.1

[PATCH v2 4/5] media: ti: cal: combine wdma irq handling

[Tomi Valkeinen]

Instead of handling the WDMA START and END interrupts separately, we
need to handle both at the same time to better manage the inherent race
conditions related to CAL interrupts.

Change the code so that we have a single function,
cal_irq_handle_wdma(), which gets two booleans, start and end, as
parameters, which allows us to manage the race conditions in the
following patch.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/platform/ti/cal/cal.c | 59 ++++++++++++-----------------
 1 file changed, 25 insertions(+), 34 deletions(-)

diff --git a/drivers/media/platform/ti/cal/cal.c b/drivers/media/platform/ti/cal/cal.c
index 783ce5a8cd79..e4355f266c58 100644
--- a/drivers/media/platform/ti/cal/cal.c
+++ b/drivers/media/platform/ti/cal/cal.c
@@ -668,22 +668,33 @@ static inline void cal_irq_wdma_end(struct cal_ctx *ctx)
 	}
 }
 
+static void cal_irq_handle_wdma(struct cal_ctx *ctx, bool start, bool end)
+{
+	if (end)
+		cal_irq_wdma_end(ctx);
+
+	if (start)
+		cal_irq_wdma_start(ctx);
+}
+
 static irqreturn_t cal_irq(int irq_cal, void *data)
 {
 	struct cal_dev *cal = data;
-	u32 status;
-
-	status = cal_read(cal, CAL_HL_IRQSTATUS(0));
-	if (status) {
-		unsigned int i;
+	u32 status[3];
+	unsigned int i;
 
-		cal_write(cal, CAL_HL_IRQSTATUS(0), status);
+	for (i = 0; i < 3; ++i) {
+		status[i] = cal_read(cal, CAL_HL_IRQSTATUS(i));
+		if (status[i])
+			cal_write(cal, CAL_HL_IRQSTATUS(i), status[i]);
+	}
 
-		if (status & CAL_HL_IRQ_OCPO_ERR_MASK)
+	if (status[0]) {
+		if (status[0] & CAL_HL_IRQ_OCPO_ERR_MASK)
 			dev_err_ratelimited(cal->dev, "OCPO ERROR\n");
 
 		for (i = 0; i < cal->data->num_csi2_phy; ++i) {
-			if (status & CAL_HL_IRQ_CIO_MASK(i)) {
+			if (status[0] & CAL_HL_IRQ_CIO_MASK(i)) {
 				u32 cio_stat = cal_read(cal,
 							CAL_CSI2_COMPLEXIO_IRQSTATUS(i));
 
@@ -694,7 +705,7 @@ static irqreturn_t cal_irq(int irq_cal, void *data)
 					  cio_stat);
 			}
 
-			if (status & CAL_HL_IRQ_VC_MASK(i)) {
+			if (status[0] & CAL_HL_IRQ_VC_MASK(i)) {
 				u32 vc_stat = cal_read(cal, CAL_CSI2_VC_IRQSTATUS(i));
 
 				dev_err_ratelimited(cal->dev,
@@ -706,32 +717,12 @@ static irqreturn_t cal_irq(int irq_cal, void *data)
 		}
 	}
 
-	/* Check which DMA just finished */
-	status = cal_read(cal, CAL_HL_IRQSTATUS(1));
-	if (status) {
-		unsigned int i;
-
-		/* Clear Interrupt status */
-		cal_write(cal, CAL_HL_IRQSTATUS(1), status);
-
-		for (i = 0; i < cal->num_contexts; ++i) {
-			if (status & CAL_HL_IRQ_WDMA_END_MASK(i))
-				cal_irq_wdma_end(cal->ctx[i]);
-		}
-	}
-
-	/* Check which DMA just started */
-	status = cal_read(cal, CAL_HL_IRQSTATUS(2));
-	if (status) {
-		unsigned int i;
-
-		/* Clear Interrupt status */
-		cal_write(cal, CAL_HL_IRQSTATUS(2), status);
+	for (i = 0; i < cal->num_contexts; ++i) {
+		bool end = !!(status[1] & CAL_HL_IRQ_WDMA_END_MASK(i));
+		bool start = !!(status[2] & CAL_HL_IRQ_WDMA_START_MASK(i));
 
-		for (i = 0; i < cal->num_contexts; ++i) {
-			if (status & CAL_HL_IRQ_WDMA_START_MASK(i))
-				cal_irq_wdma_start(cal->ctx[i]);
-		}
+		if (start || end)
+			cal_irq_handle_wdma(cal->ctx[i], start, end);
 	}
 
 	return IRQ_HANDLED;
-- 
2.34.1

[PATCH v2 5/5] media: ti: cal: fix wdma irq for metadata

[Tomi Valkeinen]

CAL HW interrupts are inherently racy. If we get both start and end
interrupts, we don't know what has happened: did the DMA for a single
frame start and end, or did one frame end and a new frame start?

Usually for normal pixel frames we get the interrupts separately. If
we do get both, we have to guess. The assumption in the code is that the
active vertical area is larger than the blanking vertical area, and thus
it is more likely that we get the end of the old frame and the start of
a new frame.

However, for embedded data, which is only a few lines high, we always
get both interrupts. Here the assumption is that we get both for the
same frame.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/media/platform/ti/cal/cal.c | 33 ++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/drivers/media/platform/ti/cal/cal.c b/drivers/media/platform/ti/cal/cal.c
index e4355f266c58..12de9171e353 100644
--- a/drivers/media/platform/ti/cal/cal.c
+++ b/drivers/media/platform/ti/cal/cal.c
@@ -670,11 +670,34 @@ static inline void cal_irq_wdma_end(struct cal_ctx *ctx)
 
 static void cal_irq_handle_wdma(struct cal_ctx *ctx, bool start, bool end)
 {
-	if (end)
-		cal_irq_wdma_end(ctx);
-
-	if (start)
-		cal_irq_wdma_start(ctx);
+	/*
+	 * CAL HW interrupts are inherently racy. If we get both start and end
+	 * interrupts, we don't know what has happened: did the DMA for a single
+	 * frame start and end, or did one frame end and a new frame start?
+	 *
+	 * Usually for normal pixel frames we get the interrupts separately. If
+	 * we do get both, we have to guess. The assumption in the code below is
+	 * that the active vertical area is larger than the blanking vertical
+	 * area, and thus it is more likely that we get the end of the old frame
+	 * and the start of a new frame.
+	 *
+	 * However, for embedded data, which is only a few lines high, we always
+	 * get both interrupts. Here the assumption is that we get both for the
+	 * same frame.
+	 */
+	if (ctx->v_fmt.fmt.pix.height < 10) {
+		if (start)
+			cal_irq_wdma_start(ctx);
+
+		if (end)
+			cal_irq_wdma_end(ctx);
+	} else {
+		if (end)
+			cal_irq_wdma_end(ctx);
+
+		if (start)
+			cal_irq_wdma_start(ctx);
+	}
 }
 
 static irqreturn_t cal_irq(int irq_cal, void *data)
-- 
2.34.1