| Message ID | 20241023085643.978729-1-laurentiu.palcu@oss.nxp.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] media: nxp: imx8-isi: better handle the m2m usage_count | expand |
Hi Laurent, I'm really sorry to keep bugging you about this patch but it looks like this one fell through the cracks again... :/ Thanks, Laurentiu On Thu, Feb 06, 2025 at 10:37:49PM +0200, Laurent Pinchart wrote: > Hi Laurentiu, > > Thank you for the patch. > > On Wed, Oct 23, 2024 at 11:56:43AM +0300, Laurentiu Palcu wrote: > > 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: cf21f328fcafac ("media: nxp: Add i.MX8 ISI driver") > > Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > > Signed-off-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com> > > --- > > v3: > > * Changed the implementation as suggested by Laurent and add a Suggested-by > > tag to reflect that; > > > > v2: > > * Changed the way 'usage_count' is incremented/decremented by taking > > into account the context the streamon/streamoff functions are called > > from; > > * Changed the commit message and subject to reflect the changes; > > > > drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c | 13 +++++++++++++ > > 1 file changed, 13 insertions(+) > > > > diff --git a/drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c b/drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c > > index 9745d6219a166..dc10e1a9f27c1 100644 > > --- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c > > +++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c > > @@ -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 { > > @@ -486,6 +487,7 @@ 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; > > @@ -495,6 +497,9 @@ static int mxc_isi_m2m_streamon(struct file *file, void *fh, > > > > While at it I'll drop the blank line here when applying the patch. > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > > > int ret; > > > > + if (q->streaming) > > + return 0; > > + > > mutex_lock(&m2m->lock); > > > > if (m2m->usage_count == INT_MAX) { > > @@ -547,6 +552,8 @@ static int mxc_isi_m2m_streamon(struct file *file, void *fh, > > goto unchain; > > } > > > > + q->streaming = true; > > + > > return 0; > > > > unchain: > > @@ -569,10 +576,14 @@ 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); > > > > /* > > @@ -598,6 +609,8 @@ static int mxc_isi_m2m_streamoff(struct file *file, void *fh, > > > > mutex_unlock(&m2m->lock); > > > > + q->streaming = false; > > + > > return 0; > > } > > > > -- > Regards, > > Laurent Pinchart
diff --git a/drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c b/drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c index 9745d6219a166..dc10e1a9f27c1 100644 --- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c +++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c @@ -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 { @@ -486,6 +487,7 @@ 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; @@ -495,6 +497,9 @@ static int mxc_isi_m2m_streamon(struct file *file, void *fh, int ret; + if (q->streaming) + return 0; + mutex_lock(&m2m->lock); if (m2m->usage_count == INT_MAX) { @@ -547,6 +552,8 @@ static int mxc_isi_m2m_streamon(struct file *file, void *fh, goto unchain; } + q->streaming = true; + return 0; unchain: @@ -569,10 +576,14 @@ 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); /* @@ -598,6 +609,8 @@ static int mxc_isi_m2m_streamoff(struct file *file, void *fh, mutex_unlock(&m2m->lock); + q->streaming = false; + return 0; }
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: cf21f328fcafac ("media: nxp: Add i.MX8 ISI driver") Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com> --- v3: * Changed the implementation as suggested by Laurent and add a Suggested-by tag to reflect that; v2: * Changed the way 'usage_count' is incremented/decremented by taking into account the context the streamon/streamoff functions are called from; * Changed the commit message and subject to reflect the changes; drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)