On Thu, Feb 4, 2016 at 2:37 PM, CK Hu <ck.hu@xxxxxxxxxxxx> wrote: > Hi Philipp: > > On Wed, 2016-02-03 at 12:01 +0100, Philipp Zabel wrote: >> Hi Daniel, >> > >> > > +static void mtk_output_dsi_disable(struct mtk_dsi *dsi) >> > > +{ >> > > + if (!dsi->enabled) >> > > + return; >> > > + >> > > + if (dsi->panel) { >> > > + if (drm_panel_disable(dsi->panel)) { >> > > + DRM_ERROR("failed to disable the panel\n"); >> > > + return; >> > > + } >> > > + } >> > > + >> > > + mtk_dsi_poweroff(dsi); >> > >> > The order is a bit suspicious here; I would expect to poweroff dsi >> > before the panel to mirror the turn on order. >> >> CK, could you comment on this? >> > > According to the experience of other Mediatek SoC, > In mtk_output_dsi_enable(), we should do power on dsi first and then > prepare panel because dsi should be ready to receive panel prepare error > message. So we should disable panel and then power off dsi in > mtk_output_dsi_disable(). Then what about the other direction? Should we be powering up dsi first before enabling the panel so DSI can receive an panel enabling errors? -Dan > >> I can reorder this, but I'm not sure about the reasoning (what happens >> hardware wise if we just cut panel power vs. if the DSI panel first sees >> the ULP transition). Further, I don't have a panel to test, just the >> PS8640. >> >> thanks >> Philipp >> >> > > Regards, > CK > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html