On Mon Mar 23 16:33:30 2026 +0800, Guoniu Zhou wrote:
> The maximum downscaling factor supported by ISI can be up to 16. Add
> minimum value constraint before applying the setting to hardware.
> Otherwise, the process will not respond even when Ctrl+C is executed.
>
> Fixes: cf21f328fcaf ("media: nxp: Add i.MX8 ISI driver")
> Cc: [email protected]
> Reviewed-by: Frank Li <[email protected]>
> Signed-off-by: Guoniu Zhou <[email protected]>
> Reviewed-by: Laurent Pinchart <[email protected]>
> Link: https://patch.msgid.link/[email protected]
> Signed-off-by: Laurent Pinchart <[email protected]>
> Signed-off-by: Hans Verkuil <[email protected]>
Patch committed.
Thanks,
Hans Verkuil
drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h | 16 ++++++++++++++++
drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c | 11 ++++++++---
drivers/media/platform/nxp/imx8-isi/imx8-isi-pipe.c | 13 ++++++++-----
3 files changed, 32 insertions(+), 8 deletions(-)
---
diff --git a/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h
b/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h
index 14d63ec36416..7547a6559d4c 100644
--- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h
+++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h
@@ -11,6 +11,7 @@
#define __MXC_ISI_CORE_H__
#include <linux/list.h>
+#include <linux/math.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/types.h>
@@ -414,4 +415,19 @@ static inline void mxc_isi_debug_cleanup(struct
mxc_isi_dev *isi)
}
#endif
+/*
+ * ISI scaling engine works in two parts: it performs pre-decimation of
+ * the image followed by bilinear filtering to achieve the desired
+ * downscaling factor.
+ *
+ * The decimation filter provides a maximum downscaling factor of 8, and
+ * the subsequent bilinear filter provides a maximum downscaling factor
+ * of 2. Combined, the maximum scaling factor can be up to 16.
+ */
+static inline unsigned int
+mxc_isi_clamp_downscale_16(unsigned int val, unsigned int max_val)
+{
+ return clamp(val, max(1U, DIV_ROUND_UP(max_val, 16)), max_val);
+}
+
#endif /* __MXC_ISI_CORE_H__ */
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 a39ad7a1ab18..de398b232d74 100644
--- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c
+++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c
@@ -509,9 +509,14 @@ __mxc_isi_m2m_try_fmt_vid(struct mxc_isi_m2m_ctx *ctx,
const enum mxc_isi_video_type type)
{
if (type == MXC_ISI_VIDEO_M2M_CAP) {
- /* Downscaling only */
- pix->width = min(pix->width, ctx->queues.out.format.width);
- pix->height = min(pix->height, ctx->queues.out.format.height);
+ const struct v4l2_pix_format_mplane *format =
+ &ctx->queues.out.format;
+
+ /* Downscaling only, by up to 16. */
+ pix->width = mxc_isi_clamp_downscale_16(pix->width,
+ format->width);
+ pix->height = mxc_isi_clamp_downscale_16(pix->height,
+ format->height);
}
return mxc_isi_format_try(ctx->m2m->pipe, pix, type);
diff --git a/drivers/media/platform/nxp/imx8-isi/imx8-isi-pipe.c
b/drivers/media/platform/nxp/imx8-isi/imx8-isi-pipe.c
index a59b9456b590..2d0843c86534 100644
--- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-pipe.c
+++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-pipe.c
@@ -641,16 +641,19 @@ static int mxc_isi_pipe_set_selection(struct v4l2_subdev
*sd,
/* Composing is supported on the sink only. */
return -EINVAL;
- /* The sink crop is bound by the sink format downscaling only).
*/
+ /*
+ * The ISI supports downscaling only, with a factor up to 16.
+ * Clamp the compose rectangle size accordingly.
+ */
format = mxc_isi_pipe_get_pad_format(pipe, state,
MXC_ISI_PIPE_PAD_SINK);
sel->r.left = 0;
sel->r.top = 0;
- sel->r.width = clamp(sel->r.width, MXC_ISI_MIN_WIDTH,
- format->width);
- sel->r.height = clamp(sel->r.height, MXC_ISI_MIN_HEIGHT,
- format->height);
+ sel->r.width = mxc_isi_clamp_downscale_16(sel->r.width,
+ format->width);
+ sel->r.height = mxc_isi_clamp_downscale_16(sel->r.height,
+ format->height);
rect = mxc_isi_pipe_get_pad_compose(pipe, state,
MXC_ISI_PIPE_PAD_SINK);
_______________________________________________
linuxtv-commits mailing list -- [email protected]
To unsubscribe send an email to [email protected]
