Re: [PATCH 02/16] gpu: ipu-cpmem: Add ipu_cpmem_set_uv_offset()

[Philipp Zabel]

Am Mittwoch, den 13.07.2016, 15:54 -0700 schrieb Steve Longerbeam:
> Hi Philipp,
> 
> On 07/08/2016 10:34 AM, Philipp Zabel wrote:
> > Am Donnerstag, den 07.07.2016, 16:03 -0700 schrieb Steve Longerbeam:
> >> Adds ipu_cpmem_set_uv_offset(), to set planar U/V offsets.
> >>
> >> Signed-off-by: Steve Longerbeam <steve_longerbeam@xxxxxxxxxx>
> >> ---
> >>  drivers/gpu/ipu-v3/ipu-cpmem.c | 7 +++++++
> >>  include/video/imx-ipu-v3.h     | 1 +
> >>  2 files changed, 8 insertions(+)
> >>
> >> diff --git a/drivers/gpu/ipu-v3/ipu-cpmem.c b/drivers/gpu/ipu-v3/ipu-cpmem.c
> >> index 6494a4d..a36c35e 100644
> >> --- a/drivers/gpu/ipu-v3/ipu-cpmem.c
> >> +++ b/drivers/gpu/ipu-v3/ipu-cpmem.c
> >> @@ -253,6 +253,13 @@ void ipu_cpmem_set_buffer(struct ipuv3_channel *ch, int bufnum, dma_addr_t buf)
> >>  }
> >>  EXPORT_SYMBOL_GPL(ipu_cpmem_set_buffer);
> >>  
> >> +void ipu_cpmem_set_uv_offset(struct ipuv3_channel *ch, u32 u_off, u32 v_off)
> >> +{
> >> +	ipu_ch_param_write_field(ch, IPU_FIELD_UBO, u_off / 8);
> >> +	ipu_ch_param_write_field(ch, IPU_FIELD_VBO, v_off / 8);
> >> +}
> >> +EXPORT_SYMBOL_GPL(ipu_cpmem_set_uv_offset);
> >> +
> > I'd prefer to avoid too much duplication in the API. Is there a reason
> > you can't use ipu_cpmem_set_yuv_planar_full?
> 
> I could, but it would be cumbersome. ipu_cpmem_set_uv_offset() is being
> called when kicking off a new tile conversion, and the stride length would
> have to be calculated all over again if I were to use ipu_cpmem_set_yuv_planar_ful().
> When kicking off a new tile conversion, the stride doesn't change, only the
> tile's buffer address, and U/V offsets for planar, need to be updated.

Ok. We'll have to change tile width and height as well, but the stride
indeed is constant.

regards
Philipp