Commit 910efa64 authored by Laurentiu Palcu's avatar Laurentiu Palcu Committed by Mauro Carvalho Chehab
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media: nxp: imx8-isi: better handle the m2m usage_count 



Currently, if streamon/streamoff calls are imbalanced we can either end up
with a negative ISI m2m usage_count (if streamoff() is called more times
than streamon()) in which case we'll not be able to restart the ISI pipe
next time, or the usage_count never gets to 0 and the pipe is never
switched off.

To avoid that, add a 'streaming' flag to mxc_isi_m2m_ctx_queue_data and use it
in the streamon/streamoff to avoid incrementing/decrementing the usage_count
uselessly, if called multiple times from the same context.

Fixes: cf21f328 ("media: nxp: Add i.MX8 ISI driver")
Cc: stable@vger.kernel.org
Suggested-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarLaurentiu Palcu <laurentiu.palcu@oss.nxp.com>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20241023085643.978729-1-laurentiu.palcu@oss.nxp.com


Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent 543f81b8

drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c

+13 −1
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ struct mxc_isi_m2m_ctx_queue_data { 
	struct v4l2_pix_format_mplane format;

	const struct mxc_isi_format_info *info;

	u32 sequence;

	bool streaming;

};



struct mxc_isi_m2m_ctx {
@@ -484,15 +485,18 @@ static int mxc_isi_m2m_streamon(struct file *file, void *fh, 
				enum v4l2_buf_type type)

{

	struct mxc_isi_m2m_ctx *ctx = to_isi_m2m_ctx(fh);

	struct mxc_isi_m2m_ctx_queue_data *q = mxc_isi_m2m_ctx_qdata(ctx, type);

	const struct v4l2_pix_format_mplane *out_pix = &ctx->queues.out.format;

	const struct v4l2_pix_format_mplane *cap_pix = &ctx->queues.cap.format;

	const struct mxc_isi_format_info *cap_info = ctx->queues.cap.info;

	const struct mxc_isi_format_info *out_info = ctx->queues.out.info;

	struct mxc_isi_m2m *m2m = ctx->m2m;

	bool bypass;



	int ret;



	if (q->streaming)

		return 0;



	mutex_lock(&m2m->lock);



	if (m2m->usage_count == INT_MAX) {
@@ -545,6 +549,8 @@ static int mxc_isi_m2m_streamon(struct file *file, void *fh, 
		goto unchain;

	}



	q->streaming = true;



	return 0;



unchain:
@@ -567,10 +573,14 @@ static int mxc_isi_m2m_streamoff(struct file *file, void *fh, 
				 enum v4l2_buf_type type)

{

	struct mxc_isi_m2m_ctx *ctx = to_isi_m2m_ctx(fh);

	struct mxc_isi_m2m_ctx_queue_data *q = mxc_isi_m2m_ctx_qdata(ctx, type);

	struct mxc_isi_m2m *m2m = ctx->m2m;



	v4l2_m2m_ioctl_streamoff(file, fh, type);



	if (!q->streaming)

		return 0;



	mutex_lock(&m2m->lock);



	/*
@@ -596,6 +606,8 @@ static int mxc_isi_m2m_streamoff(struct file *file, void *fh, 


	mutex_unlock(&m2m->lock);



	q->streaming = false;



	return 0;

}