# Re: \[PATCH\] OMAPDSS: DISPC: Add predecimation limit for TILER based rotations

- From: Tomi Valkeinen \<hidden\>
- Date: 2012-09-25 13:40:54 
- List: linux-fbdev
- Page: https://ratatoskr.run/linux-fbdev/2012/09/13463975
- Thread: https://ratatoskr.run/linux-omap/2012/09/13463974/t.md

```text
On Mon, 2012-09-24 at 12:08 +0530, Chandrabhanu Mahapatra wrote:
> In OMAP4 and OMAP5 when TILER 2D burst mode is used, a maximum of one line can
> be skipped as per the respective TRMs. The MBlockStride OCP signal, which is
> sum of ROWINC and image width in memory, is only 17 bits wide. In 2D mode TILER
> supports 8192, 16384, 32768 and 65536 values of MBlockStride. In case when 2 or
> more lines are skipped the ROWINC value exceeds 65536 resulting in OCP errors.
> So, maximum vertical predecimation achievable is 2.
> 
> Signed-off-by: Chandrabhanu Mahapatra <redacted>
> ---
>  drivers/video/omap2/dss/dispc.c |    9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)

Thanks, looks fine to me.

 Tomi

```

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