[PATCH v3 0/2] media: nxp: imx8-isi: Fix scaler rounding and downscaling limits

[Guoniu Zhou]

Patch 1/2 enforces the 16x downscaling limit to prevent out-of-bounds access.

Patch 2/2 ensures the scale factor accounts for ISI's rounding-up behavior
to avoid producing one extra output line.

Signed-off-by: Guoniu Zhou <guoniu.zhou@xxxxxxx>
---
Changes in v3:
- New patch 2/2 to fix scale factor rounding
- Replace CLAMP_DOWNSCALE_16 macro with inline function
- Adjust downscale threshold from 0x4000 to 0x2000
- Clarify downscaling limit in comment
- Link to v2: https://lore.kernel.org/all/20260228-isi-v2-1-f6f9208c6844@xxxxxxx/

Changes in v2:
- Fix possible side-effects caused by 'max_val' in CLAMP_DOWNSCALE_16 macro.
- Add space line between two paragraph in comment.
- Link to v1: https://lore.kernel.org/r/20260122-isi-v1-1-c3ec6e264f13@xxxxxxx

---
Guoniu Zhou (2):
      media: nxp: imx8-isi: Fix potential out-of-bounds issues
      media: nxp: imx8-isi: Fix scale factor calculation for hardware rounding

 drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h | 16 ++++++++++++++++
 drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c   | 13 +++++++++++--
 drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c  | 11 ++++++++---
 drivers/media/platform/nxp/imx8-isi/imx8-isi-pipe.c | 13 ++++++++-----
 4 files changed, 43 insertions(+), 10 deletions(-)
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base-commit: 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f
change-id: 20260122-isi-74f87fbb9a6f

Best regards,
-- 
Guoniu Zhou <guoniu.zhou@xxxxxxxxxxx>