On Tue, Jul 4, 2017 at 2:45 PM, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote: > On Tue, Jul 4, 2017 at 7:51 PM, Rob Clark <robdclark@xxxxxxxxx> wrote: >> The goal here is to support inheriting a display setup by bootloader, >> although there may also be some non-display related use-cases. >> >> Rough idea is to add a flag for clks and power domains that might >> already be enabled when kernel starts, and make corresponding fixups >> to clk enable/prepare_count and power-domain state so that these are >> not automatically disabled late in boot. >> >> If bootloader is enabling display, and kernel is using efifb before >> real display driver is loaded (potentially from kernel module after >> userspace starts, in a typical distro kernel), we don't want to kill >> the clocks and power domains that are used by the display before >> userspace starts. >> >> Second part will be (*waves hands*) for drm/msm to check if display >> related clocks are enabled when it is loaded, and if so use drm >> atomic framework's hooks to read back hw state to sync existing >> display state w/ software state, and skip the initial clk_enable. >> Therefore inheriting the enable done by bootloader. >> >> Obviously this should be split up into multiple patches and many >> TODOs addressed. But I guess this is enough for now to start >> discussing the approach, and in particular how drm and clock/pd >> drivers work together to handle handover from bootloader. >> >> The CLK_INHERIT_BOOTLOADER and related gsdc flag should only be set >> on leaf nodes. > > Cfr. Documentation/devicetree/bindings/display/simple-framebuffer.txt? > which afaict doesn't help for efifb.. which we have no bindings for (and would seem like a strange thing to have bindings for) BR, -R _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
