Re: [PATCH 0/7] drm/msm/dpu: simplify VBIF handling

[Konrad Dybcio]

On 2/27/26 7:36 PM, Dmitry Baryshkov wrote:
> Once Konrad asked, what is the use for VBIF_NRT. Answering to his
> question revealed that it's not actually used by the DPU driver.
> 
> There are two VBIF interfaces two memory, VBIF_RT and VBIF_NRT with
> VBIF_NRT being used only for the offscreen rotator, a separate block
> performing writeback operation with the optional 90 degree rotation.
> This block will require a separate isntance of the DPU driver, and it is
> not supported at this point.
> 
> The only exception to that rule is MSM8996, where VBIF_NRT has also been
> used for outputting all writeback data. The DPU driver don't support WB
> on that platform and most likely will not in the close feature.
> 
> The missing features don't match the extra complexity required to
> support two VBIF interfaces, so drop the second one and all the options
> to support it.
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>
> ---

This leaves a trailing 'bool is_rt' in struct dpu_vbif_set_qos_params.

I'm not sure whether/if we're going to use that specific set of functions
with rotator support, but we should probably retain (and at some point
recheck) the dpu_vbif_cfg->qos_nrt_tbl data that the catalog houses

Konrad