Generic note: please use reply-to-all instead of any other options to answer the email. You have dropped all recipients (except the freedreno@) in the message <d1a320c4-d851-ba75-ef7b-80dc369d1cfd@xxxxxxxxxxx> (and it was left unnoticed). On Fri, 2 Jun 2023 at 20:00, Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> wrote: > >> There is one option which is keep current > >> > >> 1) keep struct drm_dsc_config *msm_dsi_get_dsc_config(struct msm_dsi > >> *msm_dsi) at dsi.c > >> > >> 2) use struct msm_display_info *disp_info saved at dpu_enc to locate > >> struct msm_dsi from priv->dsi[] list (see item #3) > >> > >> 3) info.dsc = msm_dsi_get_dsc_config(priv->dsi[info.h_tile_instance[0]]); > >> > >> 4) ballistically, keep original code but move info.dsc = > >> msm_dsi_get_dsc_config(priv->dsi[i]); to other place sush as > >> atomic_check() and atomic_enable(). > >> > > 5) leave drm_dsc_config handling as is, update the dsc config from the > > DP driver as suitable. If DSC is not supported, set > > dsc->dsc_version_major = 0 and dsc->dsc_version_minor = 0 on the DP > > side. In DPU driver verify that dsc->dsc_version_major/_minor != 0. > > I am confusing with item 5) > > Currently, msm_dsi_get_dsc_config() of dsi side return dsc pointer if > dsc enabled and NULL if dsc not enabled. > > Should checking dsc == NULL is good enough to differentiate between dsc > is supported and not supported? This is called a "shared memory area". Instead of either providing a dynamic data pointer, one can provide a pointer to the static area which is filled by DP or DSI. If there is no DSC available, one flags 'data not valid' by setting major,minor to 0. > > Why need to set both dsc->dsc_version_major = 0 and > dsc->dsc_version_minor = 0 for dsc is not supported? 6) Another option (which is more in style of what is done in the vendor kernel, if I'm not mistaken): Enhance struct drm_display_mode to contain a pointer to the DSC config. Use this pointer to check whether DSC should be enabled for the particular mode or not. The panels with the static DSC configuration can use a static data pointer. -- With best wishes Dmitry
